title: Effect of rivaroxaban versus warfarin on health care costs among nonvalvular atrial fibrillation patients: observations from rivaroxaban users and matched warfarin users.
abstract: BACKGROUND
  New target-specific oral anticoagulants may have benefits, such as shorter hospital length of stay, compared to warfarin in patients with nonvalvular atrial fibrillation (NVAF). This study aimed to assess, among patients with NVAF, the effect of rivaroxaban versus warfarin on health care costs in a cohort of rivaroxaban users and matched warfarin users.
  
  
  METHODS
  Health care claims from the Humana database from 5/2011 to 12/2012 were analyzed. Adult patients newly initiated on rivaroxaban or warfarin with ≥2 atrial fibrillation (AF) diagnoses (The International Classification of Diseases, Ninth Revision, Clinical Modification: 427.31) and without valvular AF were identified. Based on propensity score methods, warfarin patients were matched 1:1 to rivaroxaban patients. Patients were observed up to end of data, end of insurance coverage, death, a switch to another anticoagulant, or treatment nonpersistence. Health care costs [hospitalization, emergency room (ER), outpatient, and pharmacy costs] were evaluated using Lin's method.
  
  
  RESULTS
  Matches were found for all rivaroxaban patients, and characteristics of the matched groups (n = 2253 per group) were well balanced. Estimated mean all-cause and AF-related hospitalization costs were significantly lower for rivaroxaban versus warfarin patients (all-cause: $5411 vs. $7427, P = 0.047; AF-related: $2872 vs. $4147, P = 0.020). Corresponding estimated mean all-cause outpatient visit costs were also significantly lower, but estimated mean pharmacy costs were significantly higher for rivaroxaban patients ($5316 vs. $2620, P < 0.001). Although estimated mean costs of ER visits were higher for rivaroxaban users compared to those of warfarin users, differences were not statistically significant. Including anticoagulant costs, mean overall total all-cause costs were comparable for rivaroxaban versus warfarin users due to cost offset from a reduction in the number and length of hospitalizations and number of outpatient visits ($17,590 vs. $18,676, P = 0.542).
  
  
  CONCLUSIONS
  Despite higher anticoagulant cost, mean overall total all-cause and AF-related cost remains comparable for patients with NVAF treated with rivaroxaban versus warfarin due to the cost offset from reduced health care resource utilization.
authors.affiliation: Groupe d'analyse, Ltée, 1000 De La Gauchetière Ouest, Bureau 1200, Montréal, QC, H3B 4W5, Canada, francois.laliberte@analysisgroup.com.
authors.forename: François
authors.initials: F
authors.lastname: Laliberté
authors.forename: Michel
authors.initials: M
authors.lastname: Cloutier
authors.forename: Concetta
authors.initials: C
authors.lastname: Crivera
authors.forename: Winnie W
authors.initials: WW
authors.lastname: Nelson
authors.forename: William H
authors.initials: WH
authors.lastname: Olson
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Schein
authors.forename: Julie
authors.initials: J
authors.lastname: Vanderpoel
authors.forename: Guillaume
authors.initials: G
authors.lastname: Germain
authors.forename: Patrick
authors.initials: P
authors.lastname: Lefebvre
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000191:economics* / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy*; D016208:Databases, Factual; D004636:Emergency Service, Hospital / Q000191:economics; D005260:Female; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000069552:Rivaroxaban / Q000191:economics* / Q000627:therapeutic use; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D014859:Warfarin / Q000191:economics* / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D000069552:Rivaroxaban