title: Use and Spending for Biologic Disease-Modifying Antirheumatic Drugs for Rheumatoid Arthritis Among US Medicare Beneficiaries.
abstract: OBJECTIVE
  Biologic therapies have assumed an important role in treating rheumatoid arthritis (RA). We sought to investigate use, spending, and patient cost-sharing for Medicare beneficiaries using biologic drugs for RA, comparing patients exposed to minimal cost-sharing because of a Part D low-income subsidy (LIS) to those facing substantial out-of-pocket costs (OOP).
  
  
  METHODS
  We performed a retrospective, nationwide study using 2009 Medicare claims for a 5% random sample of beneficiaries with RA who had at least 1 RA drug dispensed. We analyzed biologic drug utilization and costs across the Part B (medical benefit) and Part D (pharmacy benefit) programs by LIS status using multinomial regression. We also projected OOP costs as the Affordable Care Act (ACA) mandates closure of the Part D coverage gap by 2020.
  
  
  RESULTS
  Among 6,932 beneficiaries, 1,812 (26.1%) received a biologic drug. LIS beneficiaries were significantly more likely to obtain Part D home-administered biologics (relative risk ratio [RRR] 2.98, 95% confidence interval [95% CI] 2.50-3.56), while non-LIS beneficiaries were less likely to receive Part D biologic agents (RRR 0.58, 95% CI 0.48-0.69). OOP costs in Part D were lower, as expected, for LIS beneficiaries ($72 versus $3,751 per year for non-LIS). Non-LIS beneficiaries had lower costs for Part B facility-administered biologic agents (range $0-$2,584) than for Part D home-administered biologic agents. ACA reforms will narrow OOP differences between Part D and B for non-LIS beneficiaries.
  
  
  CONCLUSIONS
  In contrast to LIS beneficiaries who receive mostly Part D home-administered biologic DMARDs, nonsubsidized beneficiaries have significant cost-based incentives to obtain facility-administered biologic DMARDs through Part B. The ACA will result in only slightly lower costs for Part D biologic drugs for these beneficiaries.
authors.affiliation: University of California, San Francisco.
authors.forename: Jinoos
authors.initials: J
authors.lastname: Yazdany
authors.affiliation: University of California, San Francisco.
authors.forename: Chris
authors.initials: C
authors.lastname: Tonner
authors.affiliation: San Francisco Veterans Affairs Medical Center and University of California, San Francisco.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Schmajuk
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018501:Antirheumatic Agents / Q000191:economics*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D001685:Biological Factors / Q000191:economics*; D017047:Cost Sharing; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare / Q000191:economics*; D058991:Patient Protection and Affordable Care Act; D010818:Practice Patterns, Physicians'; D012189:Retrospective Studies; D014481:United States
chemical_list: D018501:Antirheumatic Agents; D001685:Biological Factors