Racial/Ethnic Differences in Cost-Related Nonadherence and Medicare Part D: A Longitudinal Comparison

Little is known about whether racial and ethnic disparities in cost-related medication nonadherence (CRN) have changed since the implementation of Medicare Part D. This longitudinal study examined the impact of Part D on CRN among racial and ethnic minority Medicare beneficiaries, age 65 and older. Nationally representative data were obtained from the Prescription Drug Study and Health and Retirement Study. A differences-in-differences approach was used to compare CRN among non-Hispanic Blacks, Hispanics, and non-Hispanic Whites. The results indicate CRN was higher among the two minority groups than among non-Hispanic Whites before and after Medicare Part D. Mixed-effects logistic regression analyses show that CRN did not significantly change between pre- and post-Medicare Part D for any of these three groups. However, older non-Hispanic Blacks and Hispanics had a larger reduction in CRN than non-Hispanic Whites. These findings suggest that despite Medicare Part D, racial and ethnic disparities in CRN persist.