of Studies Risk of Bias Inconsistency Indirectness Imprecision Publication Bias Study Event Rates (%) Relative Effect CI) Estimation of Absolute Effects Time Frame Quality of Evidence With ASA With VKA With ASA With VKA CI) Death (critical outcome) mean follow-up y RCTs No serious limitations No serious inconsistency No serious indirectness Imprecise b Undetected RR per c fewer death per (from fewer to more) Moderate 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 Imprecise h Undetected RR per i more bleeds per (from fewer to more) Moderate 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 embolism per (from fewer to more) Moderate (Continued) www.chestpubs.org CHEST / 141 / 2 / FEBRUARY, 2012 SUPPLEMENT e545S Table Quality Assessment Summary of Findings No. of Studies Risk of Bias Inconsistency Indirectness Imprecision Publication Bias Study Event Rates (%) Relative Effect CI) Estimation of Absolute Effects Time Frame Quality of Evidence With ASA With VKA With ASA With VKA CI) 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 . 