Using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to rate the certainty of evidence of study outcomes from systematic reviews: A quick tutorial

The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework offers a structured approach to assess the certainty of evidence (CoE) in systematic reviews (SRs). The CoE for each outcome falls into one of the four categories: very low, low, moderate, or high. The judgment of CoE is based on five downgrading factors (including the risk of bias, indirectness, inconsistency, imprecision, and publication bias) and three upgrading factors (including large effect size, dose-response relationship, and opposing plausible residual bias and confounding). To improve the transparency of SRs, authors should indicate how they grade the CoE for each outcome and provide a rationale for downgrading or upgrading the CoE.