Socioeconomic Characteristics Of Enrollees Appear To Influence Performance Scores For Medicare Part D Contractors

More than 150 private companies contract with the federal government to provide Part D prescription drug benefits to Medicare beneficiaries, either through stand-alone drug plans or as part of Medicare Advantage plans. The Centers for Medicare and Medicaid Services (CMS) evaluates these companies on a set of performance measures, including plan enrollees’ medication adherence. We used 2012 data from CMS and data from the US Census Bureau to investigate whether these performance ratings are influenced by the socioeconomic characteristics of enrollee populations. We found that some companies have a substantial advantage over others because of their enrollees’ socioeconomic characteristics, with more than a third of the variation in adherence scores tied to these characteristics. CMS should seriously consider adjusting adherence scores to account for differences in the socioeconomic characteristics of enrollee populations.