were the patients subsequently treated with warfarin?
A. Laupacis and K. Sullivan Clinical Epidemiology Unit, Loeb Medical Research Institute, Ottawa Civic Hospital, ON. OBJECTIVE: To determine the effect of the results of clinical trials on the behaviour of patients and physicians, the authors ascertained the proportion of patients participating in the Canadian Atrial Fibrillation Anticoagulation (CAFA) study who started or continued warfarin therapy at the end of the study and identified factors affecting the decision to use or not use warfarin. The CAFA study was a double-blind, randomized, placebo-controlled, multicentre study to evaluate the efficacy of warfarin in preventing stroke among patients with nonrheumatic atrial fibrillation. Recruitment and follow-up were stopped early because two other similar studies had shown a decrease in the rate of stroke among patients treated with warfarin. DESIGN: Mail survey 21 months after the end of the study. PARTICIPANTS: The personal physicians of 336 patients who had participated in the CAF
