BACKGROUND AND AIMS: Comprehensive community initiatives (CCI) are prioritised in global drug strategies to address alcohol related harms. However, their impact is unclear and moderators of impact are rarely considered. We explored CCIs that address alcohol use or related harms including approaches, effectiveness and factors that strengthen impact.

METHOD: A systematic review and meta-analysis (PROSPERO ID CRD420251044005). Embase, Medline, CINAHL, PsycINFO and the Cochrane Database of Systematic Reviews were searched. Reference lists for English-language articles were hand-searched without date restriction. A meta-analysis and qualitative synthesis were completed on any measure of alcohol use or related harms including potential moderators of impact (including community type, level of engagement, initiative combinations, duration, recency, evaluation quality and length of follow-up).

RESULTS: The systematic review included 44 studies (from 15 419 articles), with 35 assessing alcohol use and 21 assessing alcohol-related harms. Meta analysis included 15 outcome estimates from nine studies across three alcohol use outcomes: any recent (past month) alcohol use [six studies, n = 32 397, relative risk (RR) = 0.96, 95% confidence interval (CI) = 0.87-1.06, heterogeneity (I) = 85.6%], any lifetime alcohol use (three studies, n = 13 025, RR = 0.82, 95% CI = 0.63-1.08, I = 96.8%) and any recent risky drinking (six studies, n = 82 383, RR = 1.02, 95% CI = 0.95-1.10, I = 72.9%). Data were insufficient for meta-analysis of additional alcohol use (e.g. frequency) or related harms outcomes. Subgroup analyses were underpowered and did not identify clear moderators of impact. Pooled estimates were imprecise, with substantial-to-considerable heterogeneity across outcomes (I = 72.9%-96.8%; τ = 0.0049-0.0544) and findings varied across studies. CCIs showed possible small preventive effects on any alcohol use, but not on recent risky drinking. Qualitative analysis indicated that CCIs incorporating school-based or parenting components showed more consistent signals of benefit compared with other initiative combinations.

CONCLUSIONS: Conclusions on the impact of comprehensive community initiatives on alcohol use and harms remain tentative because estimates from existing studies are imprecise and findings vary across studies.