title: Impact of stated barriers on proposed warfarin prescription for atrial fibrillation: a survey of Canadian physicians.
abstract: BACKGROUND
  Atrial fibrillation (AF) is a common cardiac arrhythmia, and leading cause of ischemic stroke. Despite proven effectiveness, warfarin remains an under-used treatment in atrial fibrillation patients. We sought to study, across three physician specialties, a range of factors that have been argued to have a disproportionate effect on treatment decisions.
  
  
  METHODS
  Cross-sectional survey of Canadian Family Doctors (FD: n = 500), Geriatricians (G: n = 149), and Internal Medicine specialists (IMS: n = 500). Of these, 1032 physicians were contactable, and 335 completed and usable responses were received. Survey questions and clinical vignettes asked about the frequency with which they see patients with atrial fibrillation, treatment practices, and barriers to the prescription of anticoagulants.
  
  
  RESULTS
  Stated prescribing practices did not significantly differ between physician groups. Falls risk, bleeding risk and poor patient adherence were all highly cited barriers to prescribing warfarin. Fewer geriatricians indicated that history of patient falls would be a reason for not treating with warfarin (G: 47%; FD: 71%; IMS: 72%), and significantly fewer changed reported practice in the presence of falls risk (χ (2) (6) = 45.446, p < 0.01). Experience of a patient having a stroke whilst not on warfarin had a significant impact on vignette decisions; physicians who had had patients who experienced a stroke were more likely to prescribe warfarin (χ (2) (3) =10.7, p = 0.013).
  
  
  CONCLUSIONS
  Barriers to treatment of atrial fibrillation with warfarin affect physician specialties to different extents. Prior experience of a patient suffering a stroke when not prescribed warfarin is positively associated with intention to prescribe warfarin, even in the presence of falls risk.
authors.affiliation: Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Stuart G
authors.initials: SG
authors.lastname: Nicholls
authors.affiliation: Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada ; Ottawa Hospital Research Institute, General Campus, Clinical Epidemiology Program, Centre for Practice-Changing Research (CPCR), 501 Smyth Road, Ottawa, Ontario, Canada.
authors.forename: Jamie C
authors.initials: JC
authors.lastname: Brehaut
authors.affiliation: Ottawa Hospital Research Institute, General Campus, Clinical Epidemiology Program, Centre for Practice-Changing Research (CPCR), 501 Smyth Road, Ottawa, Ontario, Canada.
authors.forename: Rubab G
authors.initials: RG
authors.lastname: Arim
authors.affiliation: Ottawa Hospital Research Institute, General Campus, Clinical Epidemiology Program, Centre for Practice-Changing Research (CPCR), 501 Smyth Road, Ottawa, Ontario, Canada.
authors.forename: Kelly
authors.initials: K
authors.lastname: Carroll
authors.affiliation: ICES uOttawa, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Perez
authors.affiliation: Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Kaveh G
authors.initials: KG
authors.lastname: Shojania
authors.affiliation: Ottawa Hospital Research Institute, General Campus, Clinical Epidemiology Program, Centre for Practice-Changing Research (CPCR), 501 Smyth Road, Ottawa, Ontario, Canada ; Department of Medicine, University of Ottawa, The Ottawa Hospital, General Campus, 501 Smyth Road, Ottawa, Ontario, Canada.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Grimshaw
authors.affiliation: Foundation for Integrity and Responsibility in Medicine, Warren, Rhode Island, USA ; Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA.
authors.forename: Roy M
authors.initials: RM
authors.lastname: Poses