Racial/ethnic disparities in measure calculations for Part D Star Ratings among Medicare beneficiaries with diabetes, hypertension, and/or hyperlipidemia

Background: Previous literature reported racial/ethnic disparities in the measure assessment of diabetes medication adherence in the Medicare Part D Star Ratings program. Objective: This study examined the likelihood of inclusion in measure calculation across racial/ethnic groups for adherence metrics in Part D Star Ratings among individuals with diabetes, hypertension, and/or hyperlipidemia. Methods: This was a retrospective cross sectional analysis of a 10% random sample of 2017 Medicare claims linked to Area Health Resources Files. Inclusion in measure calculation was determined based on inclusion/ exclusion criteria in adherence metrics for adherence medications for diabetes, hypertension, and hyperlipidemia in Part D Star Ratings developed by the Pharmacy Quality Alliance. Logistic regression and multinomial logistic regression were used to adjust for patient/community characteristics. Results: The study sample size was 2 707 216. Compared to Non-Hispanic White (White) beneficiaries, minorities were more likely to be excluded from measure calculation among individuals with 1 condition. For example, among individuals with hypertension, compared to White individuals, the adjusted odds ratios for exclusion for Black, Hispanic, Asian/Pacific Islander and other individuals were 1.46 (95% confidence interval, or CI = 1.42-1.50), 1.38 (95% CI = 1.33-1.43), 1.28 (95% CI = 1.21-1.35), and 1.08 (95% CI = 1.02-1.15), respectively. Among individuals with more than 1 chronic condition, minorities were more likely to be included in fewer calculations for medication adherence measures. For example, among individuals with all 3 conditions, the adjusted relative risk ratios for Black, compared to White, beneficiaries for being included in 0, 1, and 2 measures, versus all 3 measures, were 2.14 (95% CI = 1.99-2.30), 1.49 (95% CI = 1.41-1.56), 1.20 (95% CI = 1.18-1.23), respectively. Conclusions: Compared to White beneficiaries, racial/ethnic minorities are more likely to be excluded from the calculation for adherence measures among individuals with diabetes, hypertension, and/or hyperlipidemia. Future studies should examine whether such disparities exacerbate existing racial/ethnic disparities in health outcomes and devise solutions for these disparities.