findings in parallel study quality. with the findings from the analyzed studies? I ls/are the authors' If not there could be potential issues with conclusions bias. justifiable? Can the study If not there could be potential issues with results be study quality. applicable to the target population? Levels of Evidence for Meta-Analvsls/Svstematlc Review 1++: High quality meta-analysis/systematic review of randomized controlled trials with very low bias risk 1+: High quality meta-analysis/systematic review of randomized controlled trials with low bias risk 1-: Meta-analysis/systematic review of randomized controlled trials with high bias risk 2++: High quality meta-analysis/systematic review of case-control or cohorts with low bias risk and highly causal relationship 2+: High quality meta-analysis/systematic review of case-control or cohorts with low bias risk and a moderatelv likely causal relatlonshlo 2-: Meta-analysis/systematic review of case-control or cohorts with a high bias risk and relationship is not likely causal II. Randomized Controlled Trial Question Yes No Comment Does the study ask a specific question? Were the If not. there could be potential issues with participants bias. randomized to treatment groups? Were both the If not, there could be potential issues with participants and the bias. investigators blind to treatment allocation? Were the treatment If not, there could be potential issues with and comparison bias. groups similar to each other? There were no significant differences. Were all outcome If not there could be potential issues with measures, study quality. measured using the best available measure for that