Risk of bias
All the eligible studies had a low risk of bias – showing a high percentage of positive answers to the questions of the JBI tool. The few negative answers were related to how the measurement was conducted, if the evaluators were trained, and the description of the comparison between the study sample and dropouts. JBI quality appraisal criteria showed that the quality score of the included studies ranged between 81% and 100%, except one study had a score of 63%. Therefore, no studies with a high risk of bias were included in this review. The risk of bias assessment is presented in Table 4.