title: Biologic disease-modifying drug treatment patterns and associated costs for patients with rheumatoid Arthritis.
abstract: OBJECTIVE
  To assess the influence of biologic treatment patterns on healthcare costs for patients with rheumatoid arthritis (RA) initiating tumor necrosis factor-α (TNF-α) antagonist therapy.
  
  
  METHODS
  Patients with 2 RA diagnoses (International Classification of Diseases, 9th ed, 714.xx), and without psoriasis or Crohn's disease, were identified in a US employer-based insurance claims database. A sample of 2545 was constructed based on an index event of initiating TNF-α antagonist therapy and 30 months of continuous enrollment. Baseline characteristics were assessed in the 6-month pre-index period and treatment patterns were determined during the 12-month post-index period. Medical service and prescription drug costs were analyzed for Months 13-24 using multivariate regression analysis to control for baseline characteristics and time-varying confounding associated with treatment and disease severity.
  
  
  RESULTS
  In the first year after TNF-α initiation, 89% used a single TNF-α antagonist; only 9% and 2% had switched TNF-α antagonists or received non-TNF biologic disease-modifying antirheumatic drugs, respectively. Descriptive analyses revealed pairwise differences between groups (p < 0.05) in baseline characteristics (comorbidities, RA-related procedure use, and prescription drug use). Controlling for observed baseline characteristics, costs were greater for those treated with multiple vs single TNF-α antagonists: annual RA-related prescription drug costs ($8,340 vs $7,058; p = 0.012), RA-related healthcare costs ($15,048 vs $13,312; p = 0.008), and total healthcare costs ($26,697 vs $21,381; p < 0.001).
  
  
  CONCLUSIONS
  In this sample, the majority of patients with RA were treated with a single TNF-α antagonist over the first year on therapy. For those who switched therapy, Year 2 RA-related and total direct healthcare costs were higher, adjusting for claims-based measures of RA disease severity.
authors.affiliation: Analysis Group Inc., 1010 El Camino Real, Suite 310, Menlo Park, CA 94025, USA. smcbride@analysisgroup.com
authors.forename: Stephan
authors.initials: S
authors.lastname: McBride
authors.forename: Khaled
authors.initials: K
authors.lastname: Sarsour
authors.forename: Leigh Ann
authors.initials: LA
authors.lastname: White
authors.forename: David R
authors.initials: DR
authors.lastname: Nelson
authors.forename: Anita J
authors.initials: AJ
authors.lastname: Chawla
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Johnston
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000191:economics* / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000191:economics*; D017281:Cost of Illness; D005260:Female; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D018501:Antirheumatic Agents; D014409:Tumor Necrosis Factor-alpha