Warfarin Treatment and Outcomes of Patients With Atrial Fibrillation in Rural and Urban Settings.

Abstract

Warfarin is an effective agent in the prevention of stroke in patients with atrial fibrillation (AF). However, it requires close monitoring with regular visits to health care facilities. To date, it is unknown whether there is a difference in warfarin utilization and outcomes between urban and rural settings. We used administrative databases to compare warfarin utilization patterns and stroke and major bleeding outcomes in rural and urban settings in a population-based cohort study of patients ≥ 65 years admitted to hospital with a diagnosis of AF in the province of Quebec, Canada, from 1999 to 2007. Patients' postal codes were used to differentiate between rural and urban settings. The cohort comprised 18,198 rural (21.8%) and 65,315 urban (78.2%) patients, with similar mean age of 79 years and a similar burden of comorbidities. Overall, there was marked underutilization of warfarin in both rural and urban settings. Warfarin-filled prescription rates were slightly higher in the rural setting (adjusted OR: 1.16, 95% CI: 1.12-1.20). In multivariable Cox regression analyses, the risk for stroke and major bleeding in rural settings was similar to that in urban settings (stroke: adjusted HR: 1.01, 95% CI: 0.95-1.09; major bleeding: adjusted HR: 1.03, 95% CI: 0.95-1.12). Patients in rural settings were slightly more likely to fill a prescription for warfarin, but they experienced similar stroke and major bleeding rates to their urban counterparts.