title: The economic burden of ischemic stroke and major hemorrhage in medicare beneficiaries with nonvalvular atrial fibrillation: a retrospective claims analysis.
abstract: BACKGROUND
  Understanding the economic implications of oral anticoagulation therapy requires careful consideration of the risks and costs of stroke and major hemorrhage. The majority of patients with atrial fibrillation (AF) are aged ≥65 years, so focusing on the Medicare population is reasonable when discussing the risk for stroke.
  
  
  OBJECTIVE
  To examine the relative economic burden associated with stroke and major hemorrhage among Medicare beneficiaries who are newly diagnosed with nonvalvular atrial fibrillation (NVAF).
  
  
  METHODS
  This study was a retrospective analysis of a 5% sample of Medicare claims data for patients with NVAF from 2006 to 2008. Patients with NVAF without any claims of AF during the 12 months before the first (index) claim for AF in 2007 (baseline period) were identified and were classified into 4 cohorts during a 12-month follow-up period after the index date. These cohorts included (1) no claims for ischemic stroke or major hemorrhage (without stroke or hemorrhage); (2) no claims for ischemic stroke and ≥1 claims for major hemorrhage (hemorrhage only); (3) ≥1 claims for ischemic stroke and no major hemorrhage claims (stroke only); and (4) ≥1 claims each for ischemic stroke and for major hemorrhage (stroke and hemorrhage). The 1-year mean postindex total all-cause healthcare costs adjusted by the Centers for Medicare & Medicaid Services Hierarchical Condition Categories (HCC) score were compared among the study cohorts.
  
  
  RESULTS
  Of the 9455 eligible patients included in this study, 3% (N = 261) of the patients had ischemic stroke claims only, 3% (N = 276) had hemorrhage claims only, and <1% (N = 13) had both during the follow-up period. The unadjusted follow-up healthcare costs were $63,781 and $64,596 per patient for the ischemic stroke only and the hemorrhage only cohorts, respectively, compared with $35,474 per patient for those without hemorrhage or stroke claims. After adjustment for HCC risk score, the mean incremental costs for patients with stroke claims only and hemorrhage claims only, relative to those without stroke or hemorrhage claims, were $26,776 (95% confidence interval [CI], $20,785-$32,767; P <.001) and $26,168 (95% CI, $20,375-$31,961; P <.001), respectively.
  
  
  CONCLUSIONS
  The economic burden of managing patients with NVAF who experience ischemic stroke and hemorrhage were similarly significant during the first year after a diagnosis of NVAF. The burden of major bleeding complications on patients, clinicians, and payers should not be overlooked, and these complications should be considered in conjunction with the cost-savings associated with ischemic stroke risk reduction in future cost-benefit evaluations of oral anticoagulation therapy.
authors.affiliation: Principal and Healthcare Consultant, Milliman, Inc, New York, NY.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Fitch
authors.affiliation: Former Associate Actuary, Milliman, Inc, New York, NY.
authors.forename: Jonah
authors.initials: J
authors.lastname: Broulette
authors.affiliation: Senior Director, Health Economics and Outcomes Research, Daiichi Sankyo, Inc, Parsippany, NJ.
authors.forename: Winghan Jacqueline
authors.initials: WJ
authors.lastname: Kwong