2.10. Synthesis of Results

The inverse variance random-effects model for meta-analyses [53,54] was used to allocate a proportionate weight to trials based on the size of their individual standard errors [55], and accounting for heterogeneity across studies [56]. The ESs were presented alongside 95% CIs and interpreted using the following thresholds [57]: <0.2, trivial; 0.2–0.6, small; >0.6–1.2, moderate; >1.2–2.0, large; >2.0–4.0, very large; >4.0, extremely large. Heterogeneity was assessed using the I² statistic, with values of <25%, 25–75%, and >75% considered to represent low, moderate, and high levels of heterogeneity, respectively [58]. Data used for meta-analysis is available in a supplementary Excel file.