Racial and ethnic disparities associated with the measure for drug-drug interactions among Medicare beneficiaries.

backgroundDrug-drug interactions (DDIs) cause many preventable hospitalizations and admissions. Efforts have been made to raise DDI awareness and reduce DDI occurrence; for example, Medicare Part D Star Ratings, a health plan quality assessment program, included a DDI measure. Previous research reported racial and ethnic disparities in health services utilization and that racial and ethnic minorities, compared with non-Hispanic whites (whites), may be less likely to be targeted for a similar measure, a Star Ratings adherence measure for diabetes medications.

objectiveThis study aimed to investigate whether any racial and ethnic disparities are associated with the DDI measure in Part D Star Ratings among Medicare populations with diabetes, hypertension, and hyperlipidemia.

methodsThis cross-sectional study analyzed a 2017 Medicare Part D data sample, including 3,960,813 beneficiaries. Because the inclusion in the denominator of the Star Ratings DDI measure was determined by the use of a list of target medications, the likelihood of using a listed target medication was compared between racial and ethnic minorities and whites. Individuals with diabetes, hypertension, and hyperlipidemia were included in the analysis owing to the high prevalence of these conditions. Patient- and community-level characteristics were adjusted by logistic regression.

resultsOf the entire study sample, 26.2% used a target medication. Compared with whites, most racial and ethnic minorities were less likely to use a target medication. For example, among individuals with diabetes, blacks, Hispanics, Asians/Pacific Islanders, and others had, respectively, 14% (odds ratio 0.86 [95% CI 0.84-0.88]), 5% (0.95 [0.93-0.98]), 12% (0.88 [0.84-0.92]), and 10% (0.90 [0.87-0.93]) lower odds compared with whites. Findings were similar among hypertension and hyperlipidemia cohorts, except that Hispanics had similar odds of use as whites.

conclusionMost racial and ethnic minorities may have lower likelihood of being targeted for the DDI measure compared with whites. Future studies should examine whether these disparities affect health outcomes and devise new DDI measures for racial and ethnic minorities.