Transcript Pregnancy Episode Grouper: Development, Validation, and Applications Mark C. Hornbrook, PhD

Pregnancy Episode Grouper:
Development, Validation, and Applications
Mark C. Hornbrook, PhD
AcademyHealth Annual Research Meeting
Washington, DC
June 9, 2008
Research Team

Reproductive Health Division,
CDC

The Center for Health Research,
KPNW

Cynthia J. Berg, MD, MPH

Mark C. Hornbrook, PhD

F. Carol Bruce, RN, MPHD

Donald J. Bachman, MS

William M. Callaghan, MD, MPH

Rachel Gold, PhD, MPH

Susan Y. Chu, PhD

Maureen C. O’Keeffe Rosetti, MS

Patricia M. Dietz, DrPH

Kimberly Vesco, MD

Selvi B. Williams, MD, MPH

Evelyn P. Whitlock, MD, MPH
2
Funding

Contract # CDC 200-2001-00074,
Task # MC2-02, “Extent of
Maternal Morbidity in a Managed
Care Setting,” from the Centers for
Disease Control and Prevention


Contract # CDC 200-2006-17832,
“Extent of Maternal Morbidity in a
Managed Care Setting”
America’s Health Insurance Plans
administered this contract
3
Maternal Health
 Over
6 million pregnancies in the US annually
 Previously, hospitalizations used as proxy for morbidity
 Today, we use a more comprehensive assessment of the
incidence and prevalence of maternal morbidity
 Changes
in medical practice have led to more outpatient treatment
for pregnancy complications
 Medical informatics now frequently include computerized clinical
and laboratory/pathology information systems
4
Objectives
 Develop
a pregnancy episode grouper algorithm using HMO
electronic data warehouse
 Identify
all pregnancies occurring in HMO members during the
study period
 Identify each pregnancy’s outcome
 Identify maternal morbidities occurring within pregnancy episodes
 Estimate the prevalence of maternal morbidity in the study population
 Develop
research and quality improvement applications
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Research Setting
 Kaiser
Permanente Northwest (KPNW), a nonprofit,
prepaid group practice HMO in the Pacific Northwest,
with 475,000 members
 Includes commercial, individual, Washington State Basic
Health Plan, Medicare, and Medicaid enrollees
 Demographically representative of the local community
 Automated ambulatory medical record system linked to
administrative, encounter, financial, and clinical
management information systems
6
Over 2/3 of pregnancies ended in live birth
and almost 1/3 in spontaneous or induced abortion
Live births create inpatient
delivery records, birth
certificates, and health
plan enrollment
records
7
Episodes
 Fundamental
unit of measure for health care phenomena
 Conceptual taxonomy
 Health

problem/illness episodes
Patient’s perspective on lived experience of health problem and related treatment
 Disease

Model of the natural course of a disease or health problem
 Care

episodes
Episodes
Clusters of utilization linked to a specific therapeutic problem/goal
 Pregnancy
 Quintessential
natural course
episode—well-defined beginning and ending points and
8
Episode Definition
 Pregnancy
= Interval between estimated date of LMP and
eight weeks after delivery/pregnancy termination
 Other potential specifications
 Entire
pregnancy episode may/may not have occurred within the
observation period
 Women had to be enrolled on outcome date or enrolled at any time
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Methods
 Diagnostic,
treatment, laboratory, pharmacy, imaging, home
health, and other databases searched for codes that could
indicate pregnancy
 Complex hierarchical decision rules to determine if a
pregnancy occurred and, if so, the outcome and the date it
began and ended
11
Electronic Data Sources

Hospital discharge abstracts

Outside professional & facility
claims and referrals

Same-day surgery records

Ambulatory encounter abstracts
or electronic medical records

Imaging procedures

Laboratory test results

Emergency department visits

Home health visits

Pharmacy dispensings

Birth certificates
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Pregnancy End Date and Outcome
 Retrospective,
omniscient logic
 Start
at the end of the pregnancy because the data are most
reliable, then work on the episodes with less data
 Diagnostic
and procedure codes and selected claims data,
and their associated dates, indicate the outcome of
pregnancy and when it ended
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Pregnancy Episodes Identified
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Ectopic Pregnancies
 Medical
termination
 Rx
= Methotrexate
 Repeat pregnancy tests until hormone levels drop to prepregnancy
levels
 Surgical
termination
 Surgical
procedure for removal of embryo
 Repeat pregnancy tests until hormone levels drop to prepregnancy
levels
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Spontaneous Losses
 Positive
pregnancy test or diagnosis
 Prenatal care encounters stop
 No delivery/termination procedure
 Many undetected if woman is not trying to get pregnant
23
Elective Losses
 Positive
pregnancy test or diagnosis
 Therapeutic abortion procedure
 Surgical
 Medical
 No
evidence of delivery within expected episode window
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Births
 Live
births
 Delivery
codes
 Infant hospital discharge
 Birth certificates
 Addition of infant to family health plan contract
 Stillbirths
 Look
at delivery codes, especially delivery complications
 No birth certificate or infant utilization data available
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Overlapping Episodes
 Overlapping
pregnancy episodes are medically impossible
 Grouper algorithm has hierarchical logic to resolve
implausible episode patterns
 Select
the most likely scenario and ignore the competing data
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Algorithm Validation: Methods
 Gold
Standard = blinded medical records abstractors
(MRAs) using actual electronic and hard-copy medical and
billing records
 Stratified sampling to obtain representation of all types of
pregnancy outcomes
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Pregnancies Missed by Algorithm
(N= 24)
ECT, 8%
SAB, 41%
TRO, 13%
TAB, 17%
LB, 21%

n = 511 women, 702 pregnancies
32
Pregnancies Missed by MRAs
TAB, 3%
(No. out of total of 38)
LB&SB, 3%
TRO, 11%
SAB, 33%
LB, 11%
LB or SB, 16%
Other, 23%
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Obstet Gynecol 2008;111:108995
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Definition:
Maternal Morbidity
 Any
condition during a pregnancy episode that adversely
affected women’s physical or psychological health
 Condition are unique to, or exacerbated by, pregnancy
 Used ICD-9-CM codes to classify morbidity into forty-six
major categories
 Clinically experienced authors reviewed all ICD-9-CM codes
and developed a list of 46 major maternal morbidity disease
classes
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Results
 Type
of morbidity varied by pregnancy outcome
 UTI
common with all outcomes
 Mental health conditions common with all outcomes,
especially stillbirth
 Anemia common with live/stillbirth
 Infections common with stillbirth
41
Most Common Maternal Morbidities by
Pregnancy Outcome
42
Percenta
10
5
Maternal Morbidities
Among
0
Live Birth Pregnancies
by Pay Source
Percentage ofAnemia
Common Maternal
AmongMental
Live Health
Birth
UTI Morbidities
Pelvic/Perineal
Complications
Conditions
Pregnancies By Pay Source
Medicaid (n=4186)
20
BHP (n=528)
Postpartum
Hemorrhage
Commercial (n=12104)
Percentage
15
10
5
0
Anemia
UTI
Medicaid (n=4186)
Pelvic/Perineal
Complications
BHP (n=528)
Mental Health
Conditions
Postpartum
Hemorrhage
Commercial (n=12104)
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Article
Am J Psych 2007;164:1515-1520
44
Percent of Women with Diagnosed Depression Before,
During, and After Pregnancy
18
15.4
16
14
% of
12
Women
10
10.4
8.7
8
6.9
6
4
2
0
Up to 39 weeks
before
During
Up to 39 weeks after
Entire period
45
Percent of Women Diagnosed with Depression who
Received Treatment Before, During, or After Pregnancy
100
90
80
% of
Women
70
60
50
40
30
Any anti-depressant
SSRIs
Mental health visit
Any treatment
20
10
0
Up to 39 weeks
before
During
Up to 39 weeks
after
Entire Period
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Maternal Depression



Depression before, during, or after
pregnancy was common (15.4%)
among women enrolled in KPNW
Depression diagnosis did not vary
substantially before (8.7%), during
(6.9%), or after (10.4%) pregnancy, but
the clinical specialty of where women
were diagnosed did
About 50% of women with depression
before pregnancy relapsed during the
postpartum period


About 50% of women diagnosed with
depression did not have any prior
history during the study period
Over 90% of women with diagnosed
depression received treatment


Anti-depressant use was common
during pregnancy
Depressed women were more likely
than non-depressed women to receive
Medicaid, to be unmarried, to have 3 or
more children, to be white, and to have
smoked during pregnancy
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New Engl J Med 2008;358:1444-53
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Pregnancy and Obesity
 Increasing
maternal BMI is associated with greater utilization
of health care, especially for pregnancies associated with
more extreme obesity (BMI >35.0)
 Almost all of this increase in utilization was related to the
increased rates of cesarean delivery, gestational diabetes,
diabetes mellitus, and hypertensive disorders among obese
pregnant women
49
Pre-Pregnancy BMI and Hospital Days in Pregnancy
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
Days
3.5
3.6
3.7
<18.5
18.5-24.9
25.0-29.9
4
4.1
30.0-34.9
35.0-39.9
4.4
40.0+
50
Pre-Pregnancy BMI and Ultrasounds in Pregnancy
8
7.5
Ultrasounds
7
6
5.4
5
4
3.5
3.7
3.9
<18.5
18.5-24.9
25.0-29.9
4.4
3
2
1
0
30.0-34.9
35.0-39.9
40.0+
51
Pre-Pregnancy BMI and MD Visits in Pregnancy
7
Visits
6
6
5
5.4
4.3
4.4
4.6
4.8
<18.5
18.5-24.9
25.0-29.9
30.0-34.9
4
3
2
1
0
35.0-39.9
40.0+
52
Pre-Pregnancy BMI and Dispensings in Pregnancy
9
Dispensings
8
7.7
7
6.3
6
4.9
5
4
3.6
3.6
<18.5
18.5-24.9
4.1
3
2
1
0
25.0-29.9
30.0-34.9
35.0-39.9
40.0+
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Diabetes Screening
 All
pregnant women who receive prenatal care are screened
for diabetes mellitus (DM)
 DM first diagnosed in pregnancy is coded as Gestational
Diabetes Mellitus (GDM)
 All women with GDM should receive post-partum blood
glucose screening
 GDM increases risk of obesity in offspring
54
Percent of Pregnancies with Confirmed Gestational
Diabetes (GDM):1999-2006 Kaiser Permanente Northwest
4
% GDM
3.5
3
2.8
3
2.9
2.9
2001
2002
2003
2.6
3.13
3.4
3.7
2.5
2
1.5
1
0.5
0
1999
2000
2004
2005
2006
55
Percent of Clinician Orders and Percent of Completed Postpartum Glucose Tests
among Confirmed Gestational Diabetes-affected Pregnancies
100
90
80
70
60
50
40
30
20
10
0
% Completed tests
% Clinician orders
79.2
79.3
74
70
57.8
41.5
56.4
46.9
50.3
28.5
9
15.9
1999
10.3
16.7
2000
10.8
2001
17
2002
2003
2004
2005
2006
56
GDM Intervention
 Adherence
to GDM screening guideline varies widely by
medical office within HMO
 Intervention
 Provider
reminders to order FBS test
 Patient reminders to obtain FBS test
 Track noncompliant women and escalate reminders to patients
and physicians
57
Limitations of Pregnancy Grouper

Missing or erroneous input data

Coding errors

Problems in rolling up billing records



Inconsistent pregnancy indicators

Multiple providers: differing
documentation styles
Pregnancies with little or no prenatal
care

Complex pregnancies with high
utilization
Use of multiple healthcare systems

Close early losses

Ectopic pregnancies and
trophoblastic disease are
inherently difficult to define
58
Conclusions
 Algorithm
error rates are nearly identical to those for the
MRAs (the gold standard)
 Algorithm can be applied to very large datasets at low
marginal cost and much below the costs of manual
chart abstraction
 Pregnancy-specific algorithm supports much more refined
and, therefore, clinically meaningful episode classification
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