Fifty studies (482 participants) meet the inclusion criteria of the review, 49 of which were quantitative and included in the analysis.
Single participant studies (38 studies): There was a statistically significant mean effect size (g=6.13, 95% CI 5.96 to 6.30). However, there was evidence of statistically significant heterogeneity (p<0.001).
Between-group studies (eight studies): There was a statistically significant mean effect size (g=0.90, 95% CI 0.63 to 1.18). Although there was no evidence of statistically significant heterogeneity, the eight studies varied widely in terms of the intervention, method of instruction, and outcome measure used.
Within-subject design (three studies): These studies were not combined in a meta-analysis. Two studies, which both focused on community participation skills, had differing effect size (g=0.78 and g=0.16).