Comparison 8. Subgroup analysis 1: Children aged five to 11 years versus children aged 12 to 18 years.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Teacher‐rated social skills	11	1271	Std. Mean Difference (IV, Random, 95% CI)	0.11 [‐0.00, 0.22]
1.1 Children aged 5 to 11 years	10	1194	Std. Mean Difference (IV, Random, 95% CI)	0.11 [‐0.01, 0.22]
1.2 Children aged 12 to 18 years	1	77	Std. Mean Difference (IV, Random, 95% CI)	0.16 [‐0.28, 0.61]