Impact of Medicare Part D on Racial Disparities in Adherence to Cardiovascular Medications among the Elderly

Medicare Part D improved medication adherence among the elderly, but to date, its effect on disparities in adherence remains unknown. We estimated Part D impact on racial/ethnic disparities in adherence to cardiovascular medications among seniors, using pooled data from the Medical Expenditure Panel Survey (2002-2010) on 14,221 Medicare recipients (65+ years) and 3,456 near-elderly controls (60-64 years). Study sample included White, Black, or Hispanic respondents who used at least one cardiovascular medication. Twelve-month adherence was measured as having an overall proportion of days covered ≥80%. Adherence disparities were defined according to the Institute of Medicine framework. Using difference-in-differences logistic regression, we found Part D to be associated with a 16-percentage-point decrease in the White-Hispanic disparity in overall adherence among seniors, net of the change among controls. Black-White disparities worsened only among men, by 21 percentage points. Increasing access and improving quality of medication use among disadvantaged seniors should remain a policy priority.