Out-of-Pocket Drug Costs and Drug Utilization Patterns of Postmenopausal Medicare Beneficiaries with Osteoporosis

Background: The Medicare Part D coverage gap has been associated with lower adherence and drug utilization and higher discontinuation. Because osteoporosis has a relatively high prevalence among Medicare-eligible postmenopausal women, we examined changes in utilization of osteoporosis medications during this coverage gap. Objectives: The purpose of this study was to investigate changes in out-of-pocket (OOP) drug costs and utilization associated with the Medicare Part D coverage gap among postmenopausal beneficiaries with osteoporosis. Methods: This retrospective analysis of 2007 pharmacy claims focuses on postmenopausal female Medicare beneficiaries enrolled in full-, partial-, or no-gap exposure standard or Medicare Advantage prescription drug plans (PDPs), retiree drug subsidy (RDS) plans, or the low-income subsidy program. We compared beneficiaries with osteoporosis who were taking teriparatide (Eli Lilly and Company, Indianapolis, Indiana) (n = 5657) with matched samples of beneficiaries who were taking nonteriparatide osteoporosis medications (NTO; n = 16,971) or who had other chronic conditions (OCC, n = 16,971). We measured average monthly prescription drug fills and OOP costs, medication discontinuation, and skipping. Results: More than half the sample reached the coverage gap; OOP costs then rose for teriparatide users enrolled in partial-or full-gap exposure plans (increase of 121% and 186%; $300 and $349) but fell for those in no-gap exposure PDPs or RDS plans (decrease of 49% and 30%; $131 and $40). OOP costs for beneficiaries in partial- or full-gap exposure PDPs increased >120% (increase of $144 and $176) in the NTO group and nearly doubled for the OCC group (increase of $124 and $151); these OOP costs were substantially lower than those for teriparatide users. Both teriparatide users and NTO group members discontinued or skipped medications more often than persons in the OCC group, regardless of plan or benefit design. Conclusion: Medication discontinuation and OOP costs among beneficiaries with osteoporosis were highest for those enrolled in Part D plans with a coverage gap. Providers should be aware of potential cost-related nonadherence among Medicare beneficiaries taking osteoporosis medications. (Am J Geriatr Pharmacother. 2011;9:241-249) (C) 2011 Elsevier HS Journals, Inc. All rights reserved.