Risk of Bias and Evidence Synthesis

Substantial heterogeneity will be defined as an I² value above 50%, leading to use of a random-effects model. Randomised controlled trials will use Cochrane Risk of Bias version 2.0, non-randomised studies will use ROBINS-I, and other designs will use Joanna Briggs Institute checklists. The certainty of evidence for each outcome will be assessed using the GRADE framework. Methodological quality will be assessed independently by two reviewers using tools matched to study design. Meta-analysis will only be performed when studies are sufficiently homogeneous in design, intervention, and outcome measures. The review will use narrative synthesis and may use quantitative synthesis when appropriate.