McAlister FA, et al. - In a population-based cohort of patients with non-valvular atrial fibrillation (NVAF) recently initiated on warfarin, researchers examined the time in therapeutic range (TTR). They observed insufficient international normalised ratio (INR) monitoring in nearly one-third of warfarin-treated patients. This could influence the initial choice of anticoagulant. Of those warfarin-treated patients who went for regular INR monitoring, 41% showed levels of control similar to that in randomised trials and this deteriorated by half over time. However, warfarin could still be a reliable anticoagulation option in patients who have already exhibited adherence with regular monitoring and good TTR.