Background:In Asian patients in RE-LY, dabigatran etexilate (DE) was as effective as warfarin, with a significantly lower bleeding risk. We evaluated the relationship between baseline renal function or CHADS₂score and efficacy or safety outcomes in these patients.Methods and Results:Asian patients (n=2,782) were categorized according to baseline renal function or CHADS₂score, and efficacy and safety outcomes were analyzed for DE (110 mg and 150 mg b.i.d.) vs. warfarin. There was an increase in the rates of stroke/systemic embolism and major bleeding with worsening renal function and CHADS₂score. For stroke/systemic embolism (primary efficacy endpoint), there was no treatment interaction for dabigatran at either 110 or 150 mg b.i.d. compared with warfarin related to patients’ baseline renal function (P_interaction=0.56 for DE 110 mg and 0.62 for DE 150 mg vs. warfarin) or CHADS₂score (P_interaction=0.68 for DE 110 mg and 0.31 for DE 150 mg vs. warfarin). For major bleeding, there was no treatment interaction by creatinine clearance category observed for either dose (P_interaction=0.60 and 0.62 for DE 110 mg and DE 150 mg, respectively). Baseline CHADS₂score had no significant effect on bleeding event rates with DE vs. warfarin.Conclusions:Bleeding and stroke rates in Asian patients varied according to renal function and CHADS₂score, but the relative benefits of DE over warfarin were preserved when analyzed by subcategories. (Circ J 2015; 79: 2138–2147)