The Effect of Quality Improvement on
Racial Disparities in Diabetes Care
Thomas D. Sequist, MD MPH
Alyce S. Adams, PhD
Fang Zhang, MS
Dennis Ross-Degnan, ScD
John Z. Ayanian, MD MPP
Division of General Medicine, Brigham and Women’s Hospital
Department of Health Care Policy, Harvard Medical School
Department of Ambulatory Care and Prevention, Harvard Medical School
Background

Gaps between evidence and quality exist
for diabetes care

Racial disparities in quality well
documented

Generic quality improvement is a potential
solution to reduce disparities
Study Goals

Assess baseline racial differences in
diabetes care within a large
multispecialty group practice

Analyze impact of generic quality
improvement efforts on existing racial
disparities
Methods – Study Site

Harvard Vanguard Medical Associates

Integrated multispecialty group practice
– 14 health centers in Boston area
– 250,000 adult patients

Generic QI efforts during 1997 to 2001
– Implemented electronic health record
– Computerized reminders to physicians
– Disease registries/ centralized outreach to patients
Methods - Study Population

Adult patients  18 years with 24 months
continuous enrollment in Harvard Pilgrim Health
Care

Diabetes diagnosis
–  1 inpatient diagnosis diabetes mellitus, or
–  2 outpatient diagnoses diabetes mellitus, or
– Dispensing of diabetes drug (insulin, oral agent)

Rolling annual cohort
– 1997 to 2001
– Diagnosis of diabetes for entire calendar year
Methods - Quality Measures

Collected from electronic medical record

Cholesterol management
– Annual lipid testing
– LDL control (< 130 mg/dL)
– Statin dispensing (pharmacy claims)

Glycemia management
– Annual HbA1c testing
– HbA1c control (< 7.0%)

Annual retinopathy screening
Methods - Analysis

Baseline (1997) racial differences in care
– Multivariate logistic regression
– GEE to account for clustering of patients
– Adjusted for age, gender

Longitudinal changes in disparities
– Similar to baseline models
– Data included for 1997 to 2001
– Race*year interaction term
Patient Characteristics
White
(n = 5,101)
Black
(n = 1,987)
p
value
60.2
53.8
<0.001
Male, %
51
41
<0.001
Long Term Enrollment*, %
74
73
0.44
Mean age, years
* Enrolled for at least 3 out of the 5 study years
% Receiving Annual LDL Testing
Annual LDL Cholesterol Monitoring
100
90
80
Adjusted p<0.001 (race*year interaction)
63
70
60
50
43
46
51
20
62
53
40
30
65
35
40
29
10
0
1997
1998
1999
2000
2001
White
Black
LDL Cholesterol Control
% Acheiving LDL < 130 mg/dL
100
90
80
Adjusted p<0.001 (race*year interaction)
70
60
50
40
40
30
20
29
18
39
21
30
19
10
0
45
9
1997
13
1998
1999
2000
2001
White
Black
Statin Use
100
% Prescribed Statin
90
Adjusted p=0.23 (race*year interaction)
80
70
60
50
40
30
22
26
20
10
15
18
1997
1998
30
23
35
39
27
30
2000
2001
0
1999
White
Black
Annual HbA1c Monitoring
% Receiving Annual HbA1c
100
90
80
79
80
77
76
77
70
76
75
74
75
76
60
White
Black
50
40
30
20
Adjusted p=0.11 (race*year interaction)
10
0
1997
1998
1999
2000
2001
HbA1c Control
% Acheiving HbA1c < 7.0%
100
90
80
Adjusted p=0.47 (race*year interaction)
70
60
50
40
34
35
37
34
36
24
26
28
27
26
1997
1998
1999
2000
2001
30
20
10
0
White
Black
Dilated Eye Exams
% Receiving Annual Eye Exam
100
90
80
75
71
68
69
71
66
63
65
66
70
60
71
50
40
30
20
10
Adjusted p=0.77 (race*year interaction)
0
1997
1998
1999
2000
2001
White
Black
Limitations

Single multispecialty group practice with
advanced EMR

Unmeasured confounding

No measures of patient experience with care
Discussion

Baseline disparities in diabetes care
– Substantial disparity in low performing measures
– No disparity in high performing measures

Cholesterol management quality improvement
– Reduction in process measure disparity
– Less marked reduction in outcome measure disparity
– Disparity in statin use persisted

Glycemia management
– No disparity in process measure
– No quality improvement in outcome measure
– Disparity in outcome measure persisted
Implications

Health care organizations can and should measure
disparities in care

Generic quality improvement may represent an
effective tool to diminish disparities
But….
 Important to monitor outcomes measures and
patterns of treatment

Persistent disparities may require specific focus on
minority health
Electronic Reminders
Centralized Patient Mailings
Changes in Cholesterol Management by Gender
Annual LDL Testing by Center*
1997
2001
White
Black
White
Black
 in Disparity
1
36
20
63
60
13
2
39
28
68
63
6
3
42
30
68
65
9
4
50
38
68
63
6
5
38
30
64
60
4
HVMA
Center
* Among centers with at least 50 black patients
LDL Control by Center*
1997
2001
White
Black
White
Black
 in Disparity
1
15
6
41
42
10
2
13
12
52
43
(8)
3
19
9
50
41
1
4
19
6
46
33
0
5
14
10
44
41
3
HVMA
Center
* Among centers with at least 50 black patients