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

Study Overview
=================
Brief Summary
-----------------
The current study aims to assess the quality of anticoagulation with warfarin in real world practice of secondary stroke prevention in Korean patients with Atrial fibrillation (AF) and to explore predictors for poor International Normalized Range (INR) control.

Detailed Description
-----------------
To assess the quality of anticoagulation with warfarin in real world practice of Korea for secondary stroke prevention in patients with AF-related Cardioembolic (CE) stroke 1) who initiated warfarin therapy and treatment at least for more than 7 days of warfarin adjustment period (warfarin-initiated cohort), and 2) who initiated and maintained warfarin therapy at least for more than 90 days after the 7 days of warfarin adjustment period (long-term warfarin-treated cohort). To explore predictors for poor INR control.

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

Conditions
-----------------
Stroke, Atrial Fibrillation

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

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Short-term Warfarin-treated cohort<br>admission due to AF-related ischemic stroke (known AF or newly detected AF) for TTR calculation, the number of consecutive INR measurements ≥3 after the 7 days of warfarin adjustment TTR evaluable days < 90 days | |
| Long-term Warfarin-treated cohort<br>admission due to AF-related ischemic stroke (known AF or newly detected AF) long-term warfarin therapy at least for more than 90 days after the 7 days of warfarin adjustment period for TTR calculation, the number of consecutive INR measurements ≥3 after the 7 days of warfarin adjustment TTR evaluable days ≥ 90 days | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time in TTR, the Percentage of Time in the Therapeutic Range of INR Between 2.0-3.0. | The primary outcome is TTR as measured by the percentage of time in the therapeutic range of INR between 2.0-3.0, using the Rosendaal linear interpolation method. | We will analyze INR data of patients who had AF-related ischemic stroke and were treated with warfarin therapy at least for more than 7 days of warfarin adjustment period. (The INR follow up duration: 1   maximum 3 years) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of INR Values in the Therapeutic Range of 2.0-3.0: Numbers of INR Values Within the Therapeutic Range by the Total Numbers of INR Measured. | The secondary outcome is the percentage of INR values in the therapeutic range of 2.0-3.0: numbers of INR values within the therapeutic range divided by the total numbers of INR measured. | We will analyze INR data of patients who had AF-related ischemic stroke and were treated with warfarin therapy at least for more than 7 days of warfarin adjustment period. (The INR follow up duration: 1   maximum 3 years) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Wafarin, Cardioembolic (CE) stroke, ischemic stroke