Management of Medicare Part D Prescription Drug Plans and Medication Adherence: A Conceptual Framework and Empirical Analysis.

BACKGROUND: Although contractors that offer prescription drug plans through the Medicare Part D program are evaluated in part on enrollees' medication adherence scores, little evidence addresses contractors' ability to influence these scores.

OBJECTIVE: We used data from the Centers for Medicare and Medicaid Services and US Census to investigate contractors' ability to influence their medication adherence scores. In accordance with a conceptual model, we hypothesized that contractors can directly and indirectly influence their medication adherence scores based on how effectively they manage prescription drug benefits for enrollees. We focused on 4 plan management variables: service reliability, stability/accuracy of drug prices, accessibility of prescription drugs, and availability of drug information. We examined indirect effects via enrollees' satisfaction with the plan.

RESEARCH DESIGN: We conducted a cross-sectional study based on 2012 data for which the contractor was the unit of analysis. We conducted path regression models that accounted for plan type (ie, Medicare Advantage vs. stand alone) and enrollee characteristics.

RESULTS: Among contractors, enrollee satisfaction scores were positively and significantly associated with medication adherence scores. Two of the 4 plan management variables were observed to have both direct and indirect effects on medication adherence scores: accessibility of prescription drugs and service reliability.

CONCLUSIONS: Our study indicates that Part D contractors do appear to have some level of influence over their medication adherence scores based on how effectively they manage prescription drug benefits for enrollees. Accessibility to prescriptions and better service delivery appear important in this regard and should be explored further in future research.