Patient cost sharing and receipt of erythropoiesis-stimulating agents through medicare part D

Medicare Part D prescription benefits cover injected medications, normally covered under Part B, when administered outside of physician offices. Erythropoiesis-stimulating agents (ESAs) used for chronic anemia management in patients with myelodysplastic syndromes (MDS) are commonly injected in a physician office but can be administered safely at home. In this study, we explored out-of-pocket (OOP) costs and receipt of Part D-covered ESAs in Medicare beneficiaries with MDS.

Patients with MDS enrolled in Medicare Parts A, B, and D were identified using diagnosis codes from 100% claims from 2006 to 2008. OOP costs for the mean erythropoietin alfa claim were compared for Parts B and D. Multivariable models examined the effect of low-income subsidy (LIS) and other Part D cost sharing on receipt of any ESA and any Part D-covered ESA.

A total of 13,117 (62.9%) of 20,848 patients received ESAs, but only 1,436 (6.9%) had any Part D claim. OOP payment was $348 under Part D versus $161 under Part B. Among patients with ESA use, those with LIS were 4× more likely to receive Part D ESAs (P < .01).

Few patients with MDS received ESAs through Part D. OOP payments required under Part D were substantially higher than under Part B. Cost sharing, as reflected by LIS receipt, likely affected decisions to prescribe ESAs outside of the physician office. Improved coordination between Part B and D benefits regarding issues of home injection of medications may create incentives that improve patient access and convenience and reduce costs associated with administration.