title: Impact of Rural Residence on Warfarin Use and Clinical Events in Patients with Non-Valvular Atrial Fibrillation: A Canadian Population Based Study.
abstract: OBJECTIVE
  We studied whether anticoagulant use and outcomes differed between rural versus urban Canadian non-valvular atrial fibrillation (NVAF) patients prior to the introduction of direct oral anticoagulant drugs.
  
  
  METHODS
  Retrospective cohort study of 25,284 adult Albertans with NVAF between April 1, 1999 and December 31, 2008.
  
  
  RESULTS
  Compared to urban patients, rural patients were older (p = 0.0009) and had more comorbidities but lower bleeding risk at baseline. In the first year after NVAF diagnosis, urban patients were less likely to be hospitalized (aOR 0.82, 95%CI 0.77-0.89) or have an emergency department visit for any reason (aOR 0.61, 95%CI 0.56-0.66) but warfarin dispensation rates (72.2% vs 71.8% at 365 days, p = 0.98) and clinical outcomes were similar: 7.8% died in both groups, 3.2% rural vs. 2.8% urban had a stroke or systemic embolism (SSE) (aOR 0.92, 95%CI 0.77-1.11), and 6.6% vs. 5.7% (aOR 0.93, 95%CI 0.81-1.06) had a bleed. Baseline SSE risk did not impact warfarin dispensation (73.0% in those with high vs. 72.8% in those with low CHADS2 score, p = 0.85) but patients at higher baseline bleeding risk were less likely to be using warfarin (69.2% high vs. 73.6% low HASBLED score, p<0.0001) in the first 365 days after diagnosis. In warfarin users, bleeding was more frequent (7.5% vs 6.2%, aHR 1.51 [95%CI 1.33-1.72]) but death or SSE was less frequent (7.0% vs 18.1%, aHR 0.60 [0.54-0.66]).
  
  
  CONCLUSIONS
  Warfarin use and clinical event rates did not differ between rural and urban NVAF patients in a universal access publically-funded healthcare system.
authors.affiliation: Department of Medicine, Division of Hematology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Michael Sean
authors.initials: MS
authors.lastname: McMurtry
authors.affiliation: Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Roopinder K
authors.initials: RK
authors.lastname: Sandhu
authors.affiliation: Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Erik
authors.initials: E
authors.lastname: Youngson
authors.affiliation: Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada; Canadian VIGOUR Center, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Ezekowitz
authors.affiliation: Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Padma
authors.initials: P
authors.lastname: Kaul
authors.affiliation: Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta, Edmonton, Alberta, Canada; Department of Medicine, Division of General Internal Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Finlay A
authors.initials: FA
authors.lastname: McAlister
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D004617:Embolism / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D016017:Odds Ratio; D063868:Patient Outcome Assessment; D011159:Population Surveillance; D012189:Retrospective Studies; D012306:Risk; D012424:Rural Population; D020521:Stroke / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D014505:Urban Population; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin