title: The Influence of Socioeconomic Status on Selection of Anticoagulation for Atrial Fibrillation.
abstract: OBJECTIVE
  Without third-party insurance, access to marketed drugs is limited to those who can afford to pay. We examined this phenomenon in the context of anticoagulation for patients with nonvalvular atrial fibrillation (NVAF).
  
  
  OBJECTIVE
  To determine whether, among older Ontarians receiving anticoagulation for NVAF, patients of higher socioeconomic status (SES) were more likely to switch from warfarin to dabigatran prior to its addition to the provincial formulary.
  
  
  METHODS
  Population-based retrospective cohort study of Ontarians aged 66 years and older, between 2008 and 2012.
  
  
  METHODS
  Socioeconomic status, as approximated by median neighborhood income.
  
  
  METHODS
  We identified two groups of older adults with nonvalvular atrial fibrillation: those who appeared to switch from warfarin to dabigatran after its market approval but prior to its inclusion on the provincial formulary ("switchers"), and those with ongoing warfarin use during the same interval ("non-switchers").
  
  
  RESULTS
  We studied 34,797 patients, including 3183 "switchers" and 31,614 "non-switchers". We found that higher SES was associated with switching to dabigatran prior to its coverage on the provincial formulary (p<0.0001). In multivariable analysis, subjects in the highest quintile were 50% more likely to switch to dabigatran than those in the lowest income quintile (11.3% vs. 7.3%; adjusted odds ratio 1.50; 95% CI 1.32 to 1.68). Following dabigatran's addition to the formulary, the income gradient disappeared.
  
  
  CONCLUSIONS
  We documented socioeconomic inequality in access to dabigatran among patients receiving warfarin for NVAF. This disparity was eliminated following the drug's addition to the provincial formulary, highlighting the importance of timely reimbursement decisions.
authors.affiliation: Department of Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.|Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Department of Laboratory Medicine and Pathobiology, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Sholzberg
authors.affiliation: Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada.|Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.|Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tara
authors.initials: T
authors.lastname: Gomes
authors.affiliation: Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.|Clinical Pharmacology and Toxicology, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: David N
authors.initials: DN
authors.lastname: Juurlink
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Yao
authors.affiliation: Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada.|Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Mamdani
authors.affiliation: Department of Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.|Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada.|Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.|Institute for Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andreas
authors.initials: A
authors.lastname: Laupacis
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000191:economics* / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D002755:Choice Behavior; D000069604:Dabigatran / Q000191:economics / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012923:Social Class; D014859:Warfarin / Q000191:economics / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D000069604:Dabigatran