Quality assessment

Included studies were assessed using the Risk of Bias In Non‐randomized Studies – on Interventions (ROBINS‐I) tool ¹⁸ . This tool categorizes the risk of bias as low, moderate, serious, critical and unclear. The Cochrane Collaboration’s tool for assessing risk of bias was used for the randomized studies (section 8.5) ¹⁹ . This tool assessed six domains: selection bias, performance bias, detection bias, attrition bias, reporting bias and other bias. Quality assessment was undertaken by one reviewer and checked by a second reviewer, and disagreements regarding the quality of a trial were resolved by consensus, or after consultation with the third reviewer (RAM). If a study’s risk of bias was serious, critical or unclear, the effect of removing this study was checked and relevant outcomes were reported.