1. 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

2. 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

3. 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

4. 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)

5. 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?

6. 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

7. Research Design & Setting Research Design Longitudinal, retrospective cohort analysis Study Setting Harvard Vanguard Medical Associates (HVMA) Harvard Pilgrim Health Care (HPHC)

8. 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)

9. 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

10. HVMA Data Sources (1992-1996) Ambulatory Medical Records Membership/ Enrollment Pharmacy Claims Clinical Encounters HbA1c Lab Results Race Identification Drug Therapy Dispensed Test Strips Demographic Info Home Address (linked by census block group) Days Enrolled PATIENT STUDY ID Census File

11. Key Measures Main independent measure Race Race (black v. white) Outcome measures Incidence of SMBG Incidence of SMBG (≥1 strip) Discontinuation of SMBG Discontinuation of SMBG ( > 180 days w/out strips) Covariates Fixed Fixed (age, sex, census-derived median HH income & educational level, drug type, BMI, HbA1c test, primary health site) Time-Varying Time-Varying (mean HbA1c values in prior month, # MD visits per month)

12. 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)

13. Pre-Policy Patient Differences Any Insulin Oral Sulfonylurea Only Black (n=264) White (n=613) Black (n=250) White (n=739) Female63.3%50.4%57.6%44.0% Mean Age52±1252±1453±1160±11 Mean BMI32.7±7.130.5±7.532.0±6.332.1±7.2 Mean HbA1c9.5±1.79.0±1.49.1±1.98.1±1.4 % Any SMBG64.8%77.8%34.0%30.8% Bold denote p<0.05

14. Initiation of SMBG

15. Black White % with SMBG phase-in

16. Est. Haz Ratio95% CI Pre-Policy Difference (Black vs. White)1.090.84,1.40 Post-Policy Difference (Black vs. White)1.35*1.05,1.72 Censoring at first insulin use or never initiated SMBG * p <0.05 Controlling for age, glycemic control, time-dependent drug use, and time- dependent number of physician visits

17. Discontinuation of SMBG

18. p<0.05 Post-Policy SMBG Initiators Discontinuation = >180 days without test strip use

19. 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

20. Limitations Missing race data Important unmeasured factors Socio-cultural factors (attitudes, perceptions, cultural beliefs/values) Duration of illness Intensity of medication use Single HMO

21. 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