Quality of Anticoagulation With Warfarin in Patient With Atrial Fibrillation for Secondary Stroke Prevention in Korea

Inclusion Criteria: Inclusion criteria for the warfarin-initiated cohort 1. Admission due to AF-related ischemic stroke 2. Initiation of warfarin therapy and treatment at least for more than 7 days of warfarin adjustment period 3. For TTR calculation, available consecutive INR values ≥3 after the 7 days of warfarin adjustment Inclusion criteria for the long-term warfarin-treated cohort 1. Admission due to AF-related ischemic stroke 2. Long-term warfarin therapy at least for more than 90 days after the 7 days of warfarin adjustment period 3. For TTR calculation, available consecutive INR values ≥3 after the 7 days of warfarin adjustment 4. TTR evaluable days ≥ 90 days Exclusion Criteria: 1. AF with mechanical valve 2. Enrollment in anticoagulation randomized clinical trial 3. Enrollment in studies affecting the target INR range.