a Quality Assessment Summary of Findings Risk of Bias Inconsistency Indirectness Imprecision Publication Bias Study Event Rates (%) Estimation of Absolute Effects y Time Frame No. of Studies With No Therapy With VKA Relative Effect CI) With No Therapy With VKA CI) Quality of Evidence Death (critical outcome) mean follow-up y RCTs No serious limitations No serious inconsistency No serious indirectness No serious imprecision Undetected RR per b fewer deaths per c (from fewer to fewer) High Nonfatal stroke (critical outcome) mean follow-up y; ischemic stroke and intracranial hemorrhage d RCTs No serious limitations No serious inconsistency No serious Indirectness No serious imprecision Undetected e f RR CHADS points High per g fewer strokes per (from fewer to fewer) CHADS point per fewer strokes per (from fewer to fewer) CHADS points per fewer strokes per (from fewer to fewer) CHADS points per fewer strokes per (from fewer to fewer) Nonfatal major extracranial bleeds (important outcome) mean follow-up y RCTs No serious limitations No serious inconsistency No serious indirectness No serious imprecision Undetected RR per h more bleeds per (from more to more) High i Systemic embolism (important outcome) mean follow-up y RCTs No serious limitations No serious inconsistency No serious Indirectness Imprecise j Undetected RR per k fewer systemic emboli per (from fewer to more) Moderate (Continued) e540S Antithrombotic Therapy for Atrial Fibrillation Table Quality Assessment Summary of Findings Risk of Bias Inconsistency Indirectness Imprecision Publication Bias Study Event Rates (%) Estimation of Absolute Effects y Time Frame No. of Studies With No Therapy With VKA Relative Effect CI) With No Therapy With VKA CI) Quality of Evidence Burden of treatment (important outcome) N/A No serious limitations No serious limitations No serious limitations No serious limitations N/A N/A N/A VKA . 