Racial Differences in the Impact of HMO Coverage of

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					    Racial Differences in the
  Impact of HMO Coverage of
    Diabetes Blood Glucose
  Monitors on Self-Monitoring

              Connie A. Mah, M.S.
    Department of Ambulatory Care & Prevention
Harvard Medical School & Harvard Pilgrim Health Care
              cmah@fas.harvard.edu
Acknowledgements
 Co-Authors:
    Stephen B. Soumerai, ScD
    Alyce S. Adams, PhD
    Dennis Ross-Degnan, ScD
 Funders:
    AHRQ
    Harvard Pilgrim Health Care Foundation
 Consultants:
    Fang Zhang, PhD
    John D. Piette, PhD
    James Meigs, MD, MPH
Background
 Disparities in diabetes health & health
 care use
     Blacks have worse glycemic control
     Blacks at greater risk of adverse outcomes

 Differences in diabetes quality of care
 & self-management
     Blacks receive lower quality of care
     Blacks face greater barriers to self-management
Coverage Policy
 Objective
   To reduce cost as a barrier
   To increase access to high quality care

 Mandated in over 38 states
 Provision of glucose monitoring devices &
    supplies
 Findings from parent evaluation study*
   Increased rates of SMBG

*Soumerai, Mah, Zhang, et al., Archives of Internal Medicine 2004 (164(6):645-52)
Key Research Questions
 Does this policy have the potential to
 narrow some of the racial disparity in
 diabetes self-management?

 Does providing free home glucose
 monitors have differential impacts on self-
 monitoring for black and white diabetes
 patients?
Purpose
 To determine whether policy increased
 initial trials of self-monitoring among black
 versus white patients

 To investigate whether patients who
 initiated self-monitoring after the policy
 continued to self-monitor thereafter
Research Design & Setting
 Research Design
     Longitudinal, retrospective cohort analysis

 Study Setting
   Harvard Vanguard Medical Associates (HVMA)
   Harvard Pilgrim Health Care (HPHC)
HPHC Coverage Policy
 Start of Implementation: Oct 1,1993

 Objective
   To motivate diabetes patients to start monitoring their
    blood glucose

 Policy Benefits
   Provision of glucose monitoring devices
   Self-management training & education
   Lower copay for up to 3 months’ supply of test strips
    (≤$5/script)
Study Cohort
  Definition of Diabetes:
    ≥ 1 hospital discharge Dx; or
    ≥ 2 outpatient Dx; or
    ≥ 1 insulin or oral sulfonylurea Rx

  Black or White race only

  Continuous enrollment (1992-1996)

  N=2,275 adult patients
HVMA Data Sources (1992-1996)
                 Race            Clinical        HbA1c Lab
             Identification     Encounters        Results


                                Ambulatory
                              Medical Records

                                                        Dispensed
                                                        Test Strips
   PATIENT                       Pharmacy
  STUDY ID                        Claims
                                                     Drug    Therapy



                                Membership/
                                 Enrollment                      Census File


         Demographic           Days Enrolled      Home Address
            Info                                (linked by census
                                                   block group)
Key Measures
 Main independent measure
   Race (black v. white)

 Outcome measures
   Incidence of SMBG (≥1 strip)
   Discontinuation of SMBG (>180 days w/out strips)

 Covariates
   Fixed (age, sex, census-derived median HH income &
    educational level, drug type, BMI, HbA1c test, primary
    health site)
   Time-Varying (mean HbA1c values in prior month, #
    MD visits per month)
Main Analytical Methods
 Kaplan-Meier & Log-Rank Tests
   Cumulative rates of initiation of SMBG
   Cumulative rates of discontinuation of SMBG

 Extended Segmented Cox Models
   Adjusting for patient-level fixed & time-varying
    covariates
   Relative (hazard) rates of initiation of SMBG
    (blacks relative to whites)
 Pre-Policy Patient Differences
                             Any          Oral Sulfonylurea
                           Insulin              Only
                      Black      White    Black      White
                     (n=264) (n=613)     (n=250) (n=739)
 Female               63.3%    50.4%     57.6%      44.0%
 Mean Age             52±12    52±14     53±11      60±11
 Mean BMI            32.7±7.1 30.5±7.5 32.0±6.3 32.1±7.2
 Mean HbA1c          9.5±1.7   9.0±1.4   9.1±1.9   8.1±1.4
 % Any SMBG           64.8%    77.8%     34.0%      30.8%

Bold denote p<0.05
Initiation of SMBG
                    Any Pre-Policy Insulin                                                                              Any Pre-Policy Oral
                     Treatment (N=567)                                                                                  Treatment (N=904)
               1                                                                                               1
              0.8        phase-in                                                                             0.8
% with SMBG




                                                                                                                         phase-in

              0.6                                                                                             0.6
              0.4                                                                                             0.4
              0.2                                                                                             0.2
               0                                                                                               0
                    Apr-92
                             Aug-92
                                      Dec-92
                                               Apr-93
                                                        Aug-93
                                                                 Dec-93
                                                                          Apr-94
                                                                                   Aug-94
                                                                                            Dec-94
                                                                                                     Apr-95



                                                                                                                    Apr-92
                                                                                                                             Aug-92
                                                                                                                                      Dec-92
                                                                                                                                               Apr-93
                                                                                                                                                        Aug-93
                                                                                                                                                                 Dec-93
                                                                                                                                                                          Apr-94
                                                                                                                                                                                   Aug-94
                                                                                                                                                                                            Dec-94
                                                                                                                                                                                                     Apr-95
                                                                     Black                                                        White
                                         Est. Haz Ratio          95% CI
Pre-Policy Difference
 (Black vs. White)                             1.09             0.84,1.40
Post-Policy Difference
 (Black vs. White)                             1.35*            1.05,1.72
Controlling for age, glycemic control, time-dependent drug use, and time-
dependent number of physician visits

Censoring at first insulin use or never initiated SMBG

* p <0.05
Discontinuation of
     SMBG
Post-Policy SMBG Initiators
                             100
    % SMBG Discontinuation




                              90
                              80
                              70
                              60
                                                                          Black (n=59)
                              50
                                                                          White (n=134)
                              40
                              30
                              20
                              10
                               0
                                   6 Months     12 Months     18 Months
                                       Months since SMBG Initiation
p<0.05
Discontinuation = >180 days without test strip use
Summary
 Trials of self-monitoring in post-policy
     increase in SMBG
     greater for blacks on oral therapy

 Persistence after initiation of SMBG in
 post-policy
    short-lived
Limitations
 Missing race data

 Important unmeasured factors
   Socio-cultural factors (attitudes, perceptions,
    cultural beliefs/values)
   Duration of illness
   Intensity of medication use

 Single HMO
Take Home Points
 Coverage is effective in engaging patients
 in SMBG particularly blacks

 Sustainability must be addressed

 Additional interventions may be necessary
 to improve long-term adherence and
 clinical outcomes