Persistence with therapy among patients treated with warfarin for atrial fibrillation

The major challenges of warfarin therapy relate to poor adherence and persistence, the need for regular monitoring, and the risk of hemorrhage. In clinical trials, persistence with warfarin treatment ranges from 75% to 79% at 1 year, but persistence in clinical practice is thought to be poorer. Small observational studies suggest that approximately one-quarter of patients cease warfarin treatment within a year of initiation. There are currently no large studies offering real-world estimates of persistence among warfarin users. The objective of this study was to examine persistence with warfarin therapy in a large population-based cohort of newly treated patients with atrial fibrillation (AF).