Comparison 6. Group 1: Peer‐led analysis.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Peer‐led ‐ 1 year or less	8		Odds Ratio (Fixed, 95% CI)	0.91 [0.56, 1.46]
1.1 Social influences curricula versus control	7		Odds Ratio (Fixed, 95% CI)	0.90 [0.56, 1.47]
1.2 Combined social competence and social influences curricula versus control	1		Odds Ratio (Fixed, 95% CI)	0.97 [0.11, 8.39]
2 Peer‐led ‐ longest follow‐up	11		Odds Ratio (Fixed, 95% CI)	0.94 [0.61, 1.47]
2.1 Social influences curricula versus control	7		Odds Ratio (Fixed, 95% CI)	0.93 [0.59, 1.47]
2.2 Combined social competence and social influences	2		Odds Ratio (Fixed, 95% CI)	0.99 [0.12, 8.00]
2.3 Multimodal curricula versus control	2		Odds Ratio (Fixed, 95% CI)	1.31 [0.16, 10.73]
3 Adult‐led ‐ 1 year or less	29		Odds Ratio (Fixed, 95% CI)	0.93 [0.83, 1.03]
3.1 Information curricula versus control	1		Odds Ratio (Fixed, 95% CI)	0.12 [0.00, 14.87]
3.2 Social influences curricula versus control	16		Odds Ratio (Fixed, 95% CI)	0.98 [0.86, 1.12]
3.3 Combined social competence and social influences curricula versus control	5		Odds Ratio (Fixed, 95% CI)	0.46 [0.26, 0.84]
3.4 Multimodal curricula versus control	5		Odds Ratio (Fixed, 95% CI)	0.89 [0.73, 1.08]
3.5 Other interventions	2		Odds Ratio (Fixed, 95% CI)	2.49 [0.10, 61.80]
4 Adult‐led ‐ longest follow‐up	56		Odds Ratio (Fixed, 95% CI)	0.88 [0.81, 0.96]
4.1 Information curricula versus control	1		Odds Ratio (Fixed, 95% CI)	0.12 [0.00, 14.87]
4.2 Social competence curricula versus control	7		Odds Ratio (Fixed, 95% CI)	0.52 [0.30, 0.88]
4.3 Social influences curricula versus control	30		Odds Ratio (Fixed, 95% CI)	0.92 [0.84, 1.01]
4.4 Combined social competence and social influences curricula versus control	7		Odds Ratio (Fixed, 95% CI)	0.47 [0.26, 0.84]
4.5 Multimodal curricula versus control	5		Odds Ratio (Fixed, 95% CI)	0.83 [0.68, 1.00]
4.6 Other interventions	6		Odds Ratio (Fixed, 95% CI)	0.91 [0.50, 1.66]