Comparison 6. Subgroup analysis: participant risk at ≥ 4 months or more of follow‐up.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Quantity of alcohol consumed	33	7971	Std. Mean Difference (Random, 95% CI)	‐0.11 [‐0.15, ‐0.06]
1.1 Higher risk only	26	6494	Std. Mean Difference (Random, 95% CI)	‐0.12 [‐0.17, ‐0.07]
1.2 All/low risk	7	1477	Std. Mean Difference (Random, 95% CI)	‐0.06 [‐0.20, 0.07]
2 Frequency of alcohol consumption	17	4377	Std. Mean Difference (Random, 95% CI)	‐0.14 [‐0.21, ‐0.07]
2.1 Higher risk only	14	3944	Std. Mean Difference (Random, 95% CI)	‐0.15 [‐0.23, ‐0.07]
2.2 All/low risk	3	433	Std. Mean Difference (Random, 95% CI)	‐0.07 [‐0.29, 0.15]
3 Binge drinking	21	5479	Std. Mean Difference (Random, 95% CI)	‐0.04 [‐0.10, 0.01]
3.1 Higher risk only	16	4352	Std. Mean Difference (Random, 95% CI)	‐0.06 [‐0.12, 0.01]
3.2 All/low risk	5	1127	Std. Mean Difference (Random, 95% CI)	‐0.00 [‐0.12, 0.12]
4 Alcohol problems	25	6868	Std. Mean Difference (Random, 95% CI)	‐0.08 [‐0.17, ‐0.00]
4.1 Higher risk only	22	6384	Std. Mean Difference (Random, 95% CI)	‐0.11 [‐0.19, ‐0.03]
4.2 All/low risk	3	484	Std. Mean Difference (Random, 95% CI)	0.14 [‐0.15, 0.43]