Characteristics of Prescription Drug Use Among Individuals With Multiple Sclerosis in the US Medicare Population.

Background: Few studies have characterized the full spectrum of prescription drug use for individuals with multiple sclerosis (MS). The objective of this study was to describe patterns and expenditures for disease-modifying therapies (DMTs) and other prescription drugs among Medicare beneficiaries with MS. Methods: Using Medicare claims data in 2014, we identified a cohort of Medicare beneficiaries with 12 months of continuous eligibility and 3 or more MS-related inpatient, outpatient, or prescription claims. We quantified the number, type, and costs of prescribed DMTs and other medications for MS-related symptoms. Medication costs were calculated according to whether beneficiaries received additional subsidies, which eliminate most out-of-pocket costs. Results: Of 43,283 Medicare beneficiaries identified with MS, 70% were DMT users. Most used self-administered DMTs (67%), and 3% used natalizumab; 93% received a supportive care medication. Among the 82% of individuals without subsidies, the annual median total and out-of-pocket DMT costs were $56,794 (interquartile range [IQR], $44,837-$62,038) and $4566 (IQR, $849-$5270), respectively. The most commonly used supportive care drugs were antidepressants (62%), opioid analgesics (50%), antispasticity drugs (47%), and anticonvulsants (46%). Annual median total and out-of-pocket costs for these drugs were $15,134 (IQR, $6571-$19,620) and $255 (IQR, $56-$877), respectively. Conclusions: Most Medicare beneficiaries with MS using DMTs face considerable out-of-pocket costs. Beneficiaries also used a significant number of medications potentially used for MS-related symptoms, although total and out-of-pocket costs were modest.