A comprehensive, structured review of all available evidence on a specific question — more rigorous and less biased than a traditional review article.Uses pre-specified, transparent criteria for identifying studies (search strategy), assessing their quality (risk of bias tools), and synthesizing their results. When combined with meta-analysis, a systematic review of RCTs represents the highest tier in the evidence hierarchy. Systematic reviews can also conclude that evidence is insufficient to make a determination — which is itself a meaningful scientific finding, not a null result.T↑ Top