Impact of medication synchronization programs on proportion of days covered (PDC) scores and Medicare Part D medication-related adherence metrics

Abstract

ObjectivesThis study aimed to determine if patients enrolled in a medication synchronization program have improvements in proportion of days covered (PDC) score for 3 of the Centers for Medicare and Medicaid Services adherence metrics medication classes: statins, renin-angiotensin-aldosterone system antagonists, and noninsulin diabetes medications. MethodsThis retrospective cohort study used data from members of a Medicare Advantage Prescription Drug plan, who took at least 1 of the key metric medications and had sufficient data to calculate a PDC score. The exposed cohort (“sync”) consisted of patients who enrolled in the medication synchronization program within the plan’s preferred pharmacy network, and the control group consisted of those who did not enroll in the program but met all other criteria. The primary end point was the change in PDC score from 2015 (baseline) to 2017 for each medication class. Secondary end points included the proportion of members with PDC scores of at least 85% and the association of adherence with annual medical and pharmacy costs. ResultsThe largest PDC score increases for the entire study population were seen in all 3 sync groups (RASA, diabetes, and statin) with corresponding statistically significant PDC score increases of 1.6%, 4.8%, and 2.9%, compared with −0.4%, 0.5%, and 1.3% changes in the control groups. In the multiple linear regression analysis, there were significant PDC score differences in the changes from baseline between the sync and control RASA, diabetes, and statin groups (P = 0.005, P = 0.01, and P < 0.001, respectively). The proportion of members achieving the acceptable PDC score threshold increased by 1.1% in the control group and by 4.1% in the sync group. ConclusionIn a population of patients with high baseline adherence, this medication synchronization program was associated with a statistically significant increase in adherence scores for statin, RASA, and noninsulin diabetes medications. There was no significant change in medical or pharmacy costs from the health plan perspective.