“Glucometrics:” Assessing Quality in Inpatient Glycemic Management “Glucometrics”: Assessing Quality in Inpatient Glycemic Management Outline 1. What is ‘quality’ inpatient glucose management? 2.
Download ReportTranscript “Glucometrics:” Assessing Quality in Inpatient Glycemic Management “Glucometrics”: Assessing Quality in Inpatient Glycemic Management Outline 1. What is ‘quality’ inpatient glucose management? 2.
Slide 1
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 2
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 3
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 4
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 5
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 6
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 7
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 8
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 9
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 10
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 11
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 12
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 13
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 14
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 15
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 16
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 17
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 18
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 19
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 20
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 21
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 22
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 23
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 24
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 25
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 26
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 27
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 28
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 29
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 30
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 31
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 32
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 33
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 34
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 35
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 36
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 37
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 38
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 39
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 40
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 41
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 42
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 43
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 44
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 45
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 46
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 2
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 3
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 4
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 5
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 6
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 7
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 8
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 9
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 10
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 11
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 12
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 13
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 14
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 15
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 16
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 17
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 18
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 19
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 20
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 21
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 22
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 23
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 24
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 25
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 26
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 27
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 28
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 29
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 30
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 31
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 32
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 33
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 34
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 35
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 36
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 37
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 38
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 39
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 40
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 41
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 42
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 43
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 44
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 45
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.
Slide 46
“Glucometrics:”
Assessing Quality in
Inpatient Glycemic Management
“Glucometrics”:
Assessing Quality in Inpatient Glycemic
Management
Outline
1. What is ‘quality’ inpatient glucose
management?
2. How should we measure it?
3. Future directions
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Recognition as
a Hospital
Priority
Administrative
support
Clinician
champion
Hyperglycemia
Committee
A Hospital Priority
Why?
• Enhance quality & patient safety
• Competitive advantage
• Cost savings
• The Joint Commission
Institution-Wide Educational Efforts
Physicians
Nursing staff
Pharmacists
Dietitians
Medical
Assistants
Patient Care
• Identification (& coding) of patients
•
Policies & procedures
– Point-of-Care BG Testing
– Institutional BG Targets (ICU, Wards)
– Hypoglycemia protocol
– ICU IV insulin protocols
– Standardized SQ insulin order sets
– Patient education tools
• “Inpatient diabetes management team”
•
Transition to outpatient care (access)
Example of a Glucometrics Report
Graphic Display of Glucometrics Data
MICU/CCU Avg BG Level By Year
160
150
140
Diabetic
All Patients
Non-Diabetic
159.9
158
152.3
150.3
144.9
141.6
141.8
149.6
141.2
133.6
130
133.9
130.8
120
2004
2005
Fiscal Year
www.aace.com/resources/igcrc
2006
2007-Q1
Graphic Display of Glucometrics Data
Diabetic Patients
Non-Diabetic Patients
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Percent
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
All Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percent
300+
200-300
151-200
111-150
81-110
51-80
0-50
% 111-150
% 81-110
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
www.aace.com/resources/igcrc
Patient 2
Patient 1
Patient 3
Patient 4
Blood Glucose (mg/dl)
500
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Measuring Inpatient Glycemic Control:
Special Issues
• Sample site (fingersticks, lab plasma glucose)
• Multiple measures during hypoglycemic or
hyperglycemic “events”
• Varying time intervals of measurement
• Timing in relationship to meals
• Effects of IV fluids (dextrose)
• How to collect glucose measurements?
• How to analyze them?
• How to present data to clinicians/adminstrators?
The 4 Spheres of a Quality Inpatient
Glucose Management Program
Metrics
• Systematic review of hospital BG data
• Analytical models
– What’s the “HbA1c” for glucose control
during a hospitalization?
Metrics Traditionally Used in
the Inpatient Glucose Literature
• Raw blood glucose (BG) average
• % of BGs within a pre-specified range
(80-110, 100-150, <180, <200 mg/dl)
• % of patients with a certain % of BGs within a pre-specified range
•
Hypoglycemia rates (<40, <50, <60, <70 mg/dl)
– % of BGs
– % of patients
•
Hyperglycemic excursions (>180, >200, >300 mg/dl)
– % of BGs
– % of patients
Malmberg 1997; Queale 1999; Capes 2000, 2001; Bhattacharrya 2002; van den Berghe 2001, 2006;
Funary 2003; Krinsley 2003; Goldberg 2004, 2005; Baldwin 2005; McCallister 2005; Kosiborod 2006
Glucometrics Project: Objectives
• Define inpatient glucose quality metrics
• Define ‘units of analysis’
• Compare metric results for the different
analytical units
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Sample
• Yale-New Haven Hospital BG data
• BG data downloaded into relational database for
analysis
– BG values
– Date / Time
– Patient ID
– Hospital ward
• Sample: One general medical ward’s March 2004
BG results (n=1,552)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Metrics Tested
• Mean / Median BG
• % BG in “favorable” range (80 - 139 mg/dl)
• % Hyperglycemia (>300 mg/dl)
• % Hypoglycemia (<60 mg/dl)
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Methods: Units of Analysis
“Ward”
n = 1,552
“Patient Stay”
n = 118
[13.2 BGs / stay]
“Patient Day”
n = 467
[3.3 BGs / day]
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
300
“ward” model
200
X
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
“patient stay model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Blood Glucose (mg/dl)
500
Patient 2
Patient 1
Patient 3
Patient 4
Patient 5
400
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Patient 2
Patient 1
Blood Glucose (mg/dl)
500
Patient 3
Patient 4
Patient 5
400
“patient day model”
300
200
100
50
0
SUN
MON
TUE
WED
THU
FRI
SAT
Mean / Median BG
200
186
182
179
180
160
162
160
MEAN
MEDIAN
158
140
120
100
80
Mean/median
of all BGs on
that ward
Mean/median
Mean/median
of each pt’s mean of each pt’s mean
BG during hosp’n BG during each day
60
40
20
0
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
% BGs Within Range (80-139 mg/dl)
50%
45%
40%
35%
33.9%
35.8%
32.2%
30%
25%
20%
15%
10%
% of the mean BGs % of the mean BGs
% of all BGs on
for each patient’s for each patient’s
ward that are
hosp. day that are
hosp’n that are
within target range
within target range within target range
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hyperglycemic Events (>300 mg/dl)
50%
45%
39.0%
40%
35%
30%
25%
20%
15%
% of all BGs on
ward that are
severely hyper
% of the patient
hospitalizations
where any BG was
severely hyper
C
% of the patient
hosp. days where
any BG was
severely hyper
21.8%
12.8%
10%
5%
0%
WARD
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT STAY
PT DAY
% Hypoglycemic Events (<60 mg/dl)
25%
20%
15%
10%
% of all BGs on
ward that are
hypo
% of the patient
hospitalizations
where any BG was
hypo
7.6%
% of the patient
hosp. days where
any BG was
hypo
4.5%
5%
1.5%
0%
WARD
PT STAY
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
PT DAY
Summary of Results
• Metrics for mean BG, median BG & the % “in target
range” are similar for all three analytical models.
• There were substantial differences between the
models for % hyperglycemia and % hypoglycemia.
– ‘WARD’ model has lowest %
– ‘PATIENT STAY’ model has highest %
– ‘PATIENT DAY’ model is intermediate
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Other Findings
• Addition of venous plasma lab glucose
measurements to fingerstick data
– Slight reduction in mean glucose values, but not
clinically meaningful
•
Deletion of 1st hospital day of blood glucose
– Slight reduction in mean glucose values, but not
clinically meaningful
• Applying glucometrics to the ICU (‘gold standard’ with
IV insulin infusion) - the realistic maximum % of
patient days within target range is probably ~ 80%
Conclusions
• Glucometrics are useful intermediate outcomes
measures of inpatient hyperglycemia management.
• Perception of performance & quality may depend
upon the unit of analysis
• All 3 Units of Analysis provide useful information
– ‘WARD’ model is the simplest; may be most
useful in operational analyses.
– ‘PATIENT STAY’ model perhaps most useful to
consumers (& risk management).
– ‘PATIENT DAY’ model may be the most
actionable by providers.
Goldberg PA et al. Diabetes Technology & Therapeutics 2006
Inpatient Diabetes Management Team:
Impact on Glucometrics (Before vs. After)
Pt-Day
Metric
Before
Consult
After
Consult
Absolute ∆
Relative ∆
Mean BG
225.1 mg/dl
182.7 mg/dl
-42.4 mg/dl
-18.8%
% in 70-149
Target Range
16.7%
35.3%
+18.6%
+111.4%
% Hyper (>299)
46.7%
22.8%
-23.9%
-51.2%
% Hypo (<70)
12.9%
13.0%
+0.1%
+0.8%
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Inpatient Diabetes Management Team:
Impact on Glucometrics (vs. Matched Controls)
IDMT
Non-IDMT
-49.5 mg/dl
-16.4 mg/dl
P < .01
P = NS
P = .03*
P = NS
Reduction in Hyperglycemia (>299)
P < .01
P = NS
Increase in Hypoglycemia (<70)
P = NS
P = NS
Mean BG Reduction
Increased cases in
70-149 target range
* McNemar’s Test
Bozzo J et al. 67th Scientific Sessions, American Diabetes Association, Chicago, IL, 2007 (576-P)
Other Proposed Metrics
“Time Average Glucose (TAG)”
300
Glucose (mg/dL) .
250
200
150
100
50
0
0
24
48
Time (hrs)
72
Persistent Hyperglycemia: An Independent
Predictor of AMI Outcomes
35
30
MACE (%)
25
Quartile 1
Quartile 2
Quartile 3
Quartile 4
20
15
10
5
0
Admission glucose
Persistent hyperglycemia
van der Horst et al. Cardiovascular Diabetology 2007.
30-day major adverse cardiac events (MACE) according to quartiles of admission glucose and persistent hyperglycemia
in MI patients. P value for trend in admission glucose is 0.023 and for persistent hyperglycemia is <0.0001.
‘Hyperglycemic Index’ As a Tool to Assess
Glucose Control: A Retrospective Study
• 10 yr analysis in a 12-bed surgical ICU
• 1779 patients (LOS >4 days)
• 65,528 glucose values
Mathijs Vogelzang, Iwan CC van der Host, Maarten WN Nijsten. Critical Care 2004; 8(3):R122-127
Glucose (mmol/L)
The “Hyperglycemic Index” (HGI)
HGI: 0.73
Time (hours)
•
Calculation of the hyperglycemic index (HGI). All measured glucose values (black dots) and their
corresponding sampling times are taken into account. The average over time is calculated for the
area (shaded) under the glucose curve for hyperglycemic values only. The normal glucose range
is indicated by the hatched area, with 6.0 mmol/L (dotted line) as the cutoff. HGI is the shaded
area divided by the total length of stay. In this case, HGI is 0.73 mmol/L, as indicated by the
dashed line. Note that normal or hypoglycemic measurements do not affect HGI, and thus, they
do not falsely lower this index.
Vogelzang et al. Critical Care 2004
Receiver Operator Characteristic (ROC) Curves
for Different Glucose Measures
ROC
HGI
0.64
Mean BG
0.62
Mean AM BG
0.61
Vogelzang et al. Critical Care 2004
http://glucometrics.med.yale.edu
Glucometrics
•
Institution: Second Hospital
Ward: Medical ICU Type: Adult Internal Medicine ICU 1/3/2005 – 2/1/2005
•
A patient’s glycemic control can be analyzed at three time resolutions. Individual glucoses measure control at the
shortest interval, the time between samples. Mean glucose measures control for the longest interval, the entire
hospital stay. A day’s mean glucose measures control for an intermediate interval, one day. Only this method
has a fixed interval which allows better comparison of one patient to another. The figures below show frequency
distributions; the dark bar on the x-axis between 70 and 149 shows a target or goal glucose range. Percentiles of
the data are shown by the lines and dot over the histogram: 5–––25 •50 75–––95
All Glucose Samples
Patient-stay Means
Glucose (mg/dL)
Patient-day Means
Glucose (mg/dL)
Glucose (mg/dL)
Patient – samples
Patient – stays
Patient – days
Number
1405
64
374
Median*
146
147
146
Mean*
160
155
159
93–275
111–229
104–258
182
118
154
731 52.0
35 54.7
199 53.2
n percent with a glucose < 70
19 1.4
7 10.9
14 3.7
n percent with a glucose >299
47 3.3
9 14.1
26 7.0
5th – 95th percentile*
Spread
n percent with 70 glucose 149 mg/dL*
* For patient-stays and patient-days, summary statistics are computed on the mean glucose of these intervals. For
example, in calculating the medians, the median {of individual patient-samples}, the median {of patient-stay means},
and the median {of patient-day means} are taken. Mean, median, percentile, and spread are stated as mg/dL.
Courtesy of Dr. Prem Thomas, Yale Center for Medical Informatics. http://glucometrics.med.yale.edu
“Glucometrics”: Assessing Quality in
Inpatient Glycemic Management
SUMMARY
1. “Quality” in inpatient glucose management needs to be
better defined.
2. Achieving it requires efforts in 4 spheres: prioritization;
education; patient care; and metrics.
3. Measures of inpatient glucose management are
dependent on the analytical methods employed.
4. It is important for the diabetes community, hospitals,
clinical investigators & the QI experts work together to
better define & validate standardized “glucometrics”
which are meaningful, fair, and actionable.