Risk of Bias and Quality Appraisal:
Two researchers (BR, SA) used the Cochrane Systematic Review Handbook to assess the risk of bias and the quality of the studies. Following this, the Mixed Method Appraisal Tool (MMAT)31 was used to evaluate the quality of included studies. This provided a validated, systematic approach to assessing the methodological quality and the risk of bias in the included studies. The results of the MMAT quality appraisal can be found in Table 1. Disagreements between reviewers’ judgements were resolved by consulting a third reviewer (SM). No studies were excluded following the quality appraisal.