Flow Chart of Study Cohort Enrollment.

<p>Patients who received treatments with warfarin or any antiplatelet agent, including aspirin and clopidogrel, were excluded from the study population. A total of 190,210 patients were finally enrolled in the study cohort with 17,595 males with CHA₂DS₂-VASc score of 1 and 9,926 females with CHA₂DS₂-VASc score of 2. Among the 17,595 male patients, there were 3,092, 9,469, and 5,034 patients in the age groups of 20 to 49, 50 to 64, and 65 to 74 years of age, respectively. Among the 9,926 female patients, there were 1,290, 5,983, and 2,653 patients in the age groups of 20 to 49, 50 to 64, and 65 to 74 years of age, respectively. There were other 10,435 males with CHA₂DS₂-VASc score of 0 and 5,984 females with CHA₂DS₂-VASc score of 1 used as the reference group, respectively. AF = atrial fibrillation; CHA₂DS₂-VASc = heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke/transient ischemic attack, vascular disease, age 65 to 74 years, female.