2.5 Statistical analysis
We performed this systematic review and meta-analysis following the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines.13,14 Treatment effects were compared using mean differences (MD) and 95% confidence intervals (CI) for continuous outcomes, and risk ratio (RR) with 95% CI for binary endpoints using the DerSimonian and Laird random-effects model. We used the Cochran Q test and I2 statistics to assess for heterogeneity; P values inferior to 0.01 were considered significant for heterogeneity. We considered I2 < 25%; 25% < I2 < 75%, and I2> 75% as low, medium and high heterogeneity, respectively. Review Manager 5.1.7 (Cochrane Centre, The Cochrane Collaboration, Denmark) was used for statistical analysis.

Sensitivity analysis

To explore the robustness of the results and identify possible outliers, we performed a leave-one-out sensitivity analysis for outcomes with high heterogeneity, by systematically removing each study from the pooled result. Additionally, another sensitivity analysis was performed by removing studies with a high risk of bias.