Transcript STANDARDISED PRESENTATION OF INTERFERENCE DATA …

STANDARDISED PRESENTATION
OF INTERFERENCE DATA FOR
LIMIT SETTING
BJ Martin, P Graham, M Roser, GRD Jones
Chemical Pathology, St Vincent’s Hospital, Sydney,
Australia
Interferences APCCB 1
Background
• Interference studies are commonly performed for
potential interferences from haemolysis, lipaemia and
icterus.
• The assessment of this data is difficult as there is no
standardised criteria for decision making in this area.
• In this poster we demonstrate a graphical presentation of
interference data to facilitate the process of setting
interference limits.
Interferences APCCB 2
Methods - Samples
• Interference data was generated as follows:
• In-vitro haemolysis model:
– Fresh haemolysate at various concentrations from a
single donor was added to serum pools.
– Fresh haemolysates from different donors were added
to a single serum pool at a single concentration.
• Lipaemia Model:
– Intralipid™ was added to serum pools at various
concentrations.
• Samples were measured on an Olympus AU2700 analyser
with user-defined quantitative “H” and “L” indices
Interferences APCCB 3
Methods – Olympus Indices
• Serum Indices for Haemolysis (H) and Lipaemia (L) were set
up on an Olympus AU2700:
– Two additional tests were installed (APP and APP1)
– Wavelengths: APP 570 (primary) / 600 (secondary)
– Wavelengths: APP1 600 (primary) / 700 (secondary)
– Sample volume: 6uL, reagent volume (saline): 125 uL
• Calculations
– L = 88.95 * APP1
– H = 3773.12* (APP – (1.25* (APP2))
• These quantitative indices were based on Hitachi serum
indices and are used in place of the Olympus proprietary
semi-quantitative indices.
Interferences APCCB 4
Methods - Spreadsheet
• Interference data was entered into an Excel spreadsheet
application.
• Other Inputs
– RCPA-AACB QAP Allowable Limits of Performance
(ALP)
– Within-individual Biological Variation (CVwi)
– Instrument / method / setup criteria
– Date of interference data
• The aim of the application is to display all the required
information for decision making on the same screen or
printout.
Interferences APCCB 5
Application Display
• Graphical displays
– Raw data
– Data expressed as absolute and fractional changes
– Multiple data sets of serial interference addition
(up to 3 at a time)
– Multiple sets of individual haemolysate preparations
(up to 18 different haemolysates)
• On the same graphs was displayed:
– the RCPA-AACB QAP allowable limits of performance
– The within-person biological variation.
• The chart included
– Analytical method, date, catalog number
– Analytical CV
Interferences APCCB 6
Application Use
• Change analytes for review in 2 or 3 keystrokes
• Select data sets by single letter codes
• Review current cutoffs and review alternate cutoffs
– Graphically
– Numerically
(requires selection of data set by single letter code)
• Allows direct comparison of data sets according to:
– Instrument
– Date
– Method
– Type
Interferences APCCB 7
TEST: Creatine Kinase
10
Raw Data
500
450
400
350
A
300
B
250
C
200
D
150
E
Cuttoffs
Current
250
Proposed
500
CV(wi)
22.0%
CV(a)
3.0%
Exp change*
16
Exp change*
32
15 to 16
Data Set
C
31 to 33
* if linear
Dec.Pl.
0
100
50
Data Set
A
B
C
D
E
0
0
200
400
600
800
1000
1200
1400
1600
Absolute Change
Instrument
AU2700
AU2700
AU2700
AU2700
AU2700
Date
2-May-04
2-May-04
2-May-04
5-May-04
5-May-04
Supplier
Olympus
Olympus
Olympus
Olympus
Olympus
Method
IFCC
IFCC
IFCC
IFCC
IFCC
Cat #
Type
OSR6279 Same RBCs
OSR6279 Same RBCs
OSR6279 Same RBCs
OSR6279 Diff RBCs
OSR6279 Diff RBCs
Dashed
horizontal
lines:
ALP
120
100
80
60
40
20
0
-20 0
200
400
600
800
1000
1200
1400
1600
-40
-60
Vertical
lines:
Green current
Black proposed
-80
Change per 1000H
Average
STDEV
52.07
7.22
68.7
37.1
Slope*1000
Correl
A
48.150
1.00
B
61.585
1.00
C
63.677
1.00
Data set
D
E
Relative Change
1.3
Dashed
horizontal
lines:
ALP
1.2
1.1
Yellow
+/- CVwi
1
0.9
0.8
0.7
0
200
400
600
800
1000
1200
1400
1600
Vertical
lines:
Green current
Black proposed
Available Data Sets:
A
AU2700
B
AU2700
C
AU2700
D
AU2700
E
AU2700
F
AU2700
G
Modular
H
Modular
I
Modular
J
H917
K
H917
Creatine Kinase
2-May-04 Same RBCs
2-May-04 Same RBCs
2-May-04 Same RBCs
5-May-04
Diff RBCs
5-May-04
Diff RBCs
1-Apr-02 Same RBCs
1-Jan-04
Diff RBCs
1-Jan-04
Diff RBCs
1-Jan-04
Diff RBCs
1-Jan-00
Diff RBCs
1-Jan-00
Diff RBCs
Interferences APCCB 8
Current &
proposed
cutoffs
Test Name
TEST: Creatine Kinase
10
Raw Data
500
450
400
Raw
Data
350
A
300
B
250
C
200
D
150
E
50
0
200
400
600
800
1000
1200
1400
100
80
60
40
20
200
400
600
800
1000
1200
1400
1600
-40
-60
Vertical
lines:
Green current
Black proposed
-80
Data Set
C
Data set
details
31 to 33
* if linear
Dec.Pl.
0
Instrument
AU2700
AU2700
AU2700
AU2700
AU2700
Date
2-May-04
2-May-04
2-May-04
5-May-04
5-May-04
Supplier
Olympus
Olympus
Olympus
Olympus
Olympus
Method
IFCC
IFCC
IFCC
IFCC
IFCC
Cat #
Type
OSR6279 Same RBCs
OSR6279 Same RBCs
OSR6279 Same RBCs
OSR6279 Diff RBCs
OSR6279 Diff RBCs
Change per 1000H
Average
STDEV
52.07
7.22
68.7
37.1
Slope*1000
Correl
A
48.150
1.00
B
61.585
1.00
C
63.677
1.00
Data set
D
E
Relative Change
1.3
Dashed
horizontal
lines:
ALP
1.2
1.1
Yellow
+/- CVwi
1
0.9
0.8
0.7
0
Relative
Change
15 to 16
Dashed
horizontal
lines:
ALP
120
0
-20 0
Proposed
Cuttoff
Exp change*
16
Exp change*
32
Data Set
A
B
C
D
E
1600
Absolute Change
Current
Cuttoff
Cuttoffs
Current
250
Proposed
500
CV(wi)
22.0%
CV(a)
3.0%
100
0
Absolute
Change
Calculated
effects
200
400
600
800
1000
1200
1400
ALP
Color coded
1600
Vertical
lines:
Green current
Black proposed
Available Data Sets:
A
AU2700
B
AU2700
C
AU2700
D
AU2700
E
AU2700
F
AU2700
G
Modular
H
Modular
I
Modular
J
H917
K
H917
Creatine Kinase
2-May-04 Same RBCs
2-May-04 Same RBCs
2-May-04 Same RBCs
5-May-04
Diff RBCs
5-May-04
Diff RBCs
1-Apr-02 Same RBCs
1-Jan-04
Diff RBCs
1-Jan-04
Diff RBCs
1-Jan-04
Diff RBCs
1-Jan-00
Diff RBCs
1-Jan-00
Diff RBCs
Calculation
Data
Available
Data sets for
analyte
Interferences APCCB 9
AU2700 Assay Setup
Date:
5-Aug-04
(all volumes in uL)
Test
Supplier
Method
Table 1: AU2700 assay parameters and Limits for H and L indices
Cat #
Samp
Vol
Alb
IS
BCG
IS3138
1.6
ALP
Olympus
IFCC(pNPP)
OSR6204
1.8
ALT
Olympus
IFCC (no P5P) OSR6107
5.0
Amyl
Olympus
CNPG3
OSR6106
1.6
AST
IS
IFCC (no P5P) IS3131
8.0
Bicarb IS
PEPC
IS4140
1.6
Bili-t
IS
DPD
IS3114
8.0
Ca
Olympus
o-CresolphthaleineOSR6113
3.7
Chol
IS
CholOxidase
IS3125
1.6
CK
Olympus
IFCC
OSR6279
2.5
Cl
Olympus
ISE
MU9196
20.0
Creat
Olympus
Jaffe
OSR6178
8.0
EtOH
DRI
Alc dehydrogenase
DRI 0037
9.0
Fe
Olympus
TPTZ (triazin)
OSR6186
12
Ferr
Roche
Imm-turb
1661400
4.0
GGT
Olympus
Szasz(IFCC)
OSR6219
4.0
Glucose Olympus
Hexokinase
OSR6121
2.0
HDL
Olympus
PEG Chol esterase
OSR6287
and oxidase1.6
K
Olympus
ISE
MU9195
20.0
Lact
BioMerieux Lactate oxidase 61192.0
1.6
Lase
Roche
1,2diGlyceride substrate
L1821792
1.9
LDH
Olympus
P to L
OSR6126
1.8
MG
Roche
Xylidyl Blue
L1551353
3.5
Na
Olympus
ISE
MU9194
20.0
Phos
IS
Heptamolybdate IS3136
3.3
Prot
IS
Biuret
IS3160
3.0
Trans Olympus
Endpoint
OSR6152
1.6
Trig
IS
Lipase
IS3122
1.6
UA
Olympus
UricasePAP
OSR6136
1.6
Urea
Olympus
Urease, glutamateOSR6234
dehydrogenase
2.0
Lipaemic Limit: ultracentifuge all samples with L index >5
R1
Vol
32
36
50
160
120
32
120
45
32
100
0
48
75
30
125
50
50
144
0
120
120
60
117
0
125
120
28
160
60
40
Dil1
Vol
128
36
25
0
0
128
0
80
128
0
5
36
0
101
0
13
150
0
5
0
0
15
0
5
0
0
132
0
60
30
R2
Vol
0
36
25
0
0
0
120
45
0
25
0
48
75
30
125
50
25
48
0
0
72
30
117
0
25
30
32
0
40
40
Dil2 LRL
Vol
0
15
36
10
25
5
0
10
0
5
0
10
0
0
10
1.2
0
0
0
30
0
75
0 0.030
0
0.00
10
3
0
20
13
5
25
2
0
0.2
5
2.5
0
0.2
0
3
45
50
0
0.4
5
130
0
0.3
0
10
64
1.1
0
0
0
0.1
10
1
URL
60
1500
500
2000
400
50
340
4.5
20
2000
118
2.2
0.6
179
450
1200
45
4.65
6.5
10
300
3000
2
155
5
150
7.5
10
1.79
50
Wavelengths
WL1 WL2 Method
600
410
340
410
340
380
540
570
520
340
800
480
660
480
410
410
660
660
600
660
520
340
600
700
410
340
600
800
410
800
480
380
700
480
570
340
520
800
700
660
600
340
540
380
520
520
340
600
660
800
600
660
660
Endpoint
Rate
Rate
Rate
Rate
Endpoint
Endpoint
Endpoint
Endpoint
Rate
ISE
Fixed
Rate
Endpoint
Endpoint
Rate
Endpoint
Endpoint
ISE
Endpoint
Rate
Rate
Endpoint
ISE
Endpoint
Endpoint
Endpoint
Endpoint
Endpoint
Rate
Units
g/L
U/L
U/L
U/L
U/L
mmol/L
umol/L
mmol/L
mmol/L
U/L
mmol/L
mmol/L
%
umol/L
ug/L
U/L
mmol/L
mmol/L
mmol/L
mmol/L
U/L
U/L
mmol/L
mmol/L
mmol/L
g/L
0
mmol/L
mmol/L
mmol/L
Haem
Limit
800
500
500
800
130
500
160
250
1000
250
500
1500
800
800
0
800
500
0
100
1000
1500
40
1500
500
800
500
1500
1000
500
1500
Lip
Limit
5
5
if flag
5
if flag
5
3 (bili<100)
5
5
5
5
5
5
5
0
5
5
0
5
5
5
5
5
5
5
5
5
5
5
5
Interferences APCCB 10
Conclusions
• We have developed a spreadsheet application allowing easy
graphical display of multiple data sets for interpretation of
interference data.
• The data demonstrated has been generated on an Olympus
AU2700 using user-defined, quantitative serum indices.
• The application allows improved target setting for allowable
interference limits.
Interferences APCCB 11