Two of us (H.S. and K.V.) independently extracted data and assessed the risk of bias for each of the articles. Once this was done, the forms containing the assessments were exchanged and reviewed for comparison. Any disagreements were again resolved by discussion and consensus, with the senior author (L.L.) serving as the final arbiter if consensus could not be reached. If studies had apparent contradictions that could not be resolved during data extraction (eg, bleeding definition varied within the same article) or did not report the results of their predefined outcomes sufficiently to allow inclusion in our meta-analyses (eg, SDs not given), the study’s authors were contacted.