Novel anticoagulants in an older and frail population with atrial fibrillation: the effect of inappropriate dosing on clinical outcomes

Key summary points Aim To evaluate the proportion of patients underdosed (prescribed a reduced dose despite lack of indication) with a novel oral anticoagulant (NOAC) in an older and frail population with atrial fibrillation (AF). Findings Around half (51%) of patients received a reduced dose despite lacking formal criteria for dose reduction. Adjusted combined stroke, systemic embolism and major bleeding event rate was higher in underdosed patients, but not adjusted survival. Message A very significant proportion of frail and older patients with AF remains under an inappropriately reduced-dosed NOAC, and these patients have a worse prognosis.