Findings on the effects of alcohol warning labels (AWLs) as a harm reduction tool have been mixed. This systematic review synthesized extant literature on the impact of AWLs on proxies of alcohol use. PsycINFO, Web of Science, PubMED, and MEDLINE databases and reference lists of eligible articles. Following PRISMA guidelines, 1,589 articles published prior to July 2020 were retrieved via database and 45 were via reference lists (961 following duplicate removal). Article titles and abstracts were screened, leaving the full text of 96 for review. The full-text review identified 77 articles meeting inclusion/exclusion criteria which are included here. Risk of bias among included studies was examined using the Evidence Project risk of bias tool. Findings fell into five categories of alcohol use proxies including knowledge/awareness, perceptions, attention, recall/recognition, attitudes/beliefs, and intentions/behavior. Real-world studies highlighted an increase in AWL awareness, alcohol-related risk perceptions (limited findings), and AWL recall/recognition post-AWL implementation; these findings have decreased over time. Conversely, findings from experimental studies were mixed. AWL content/formatting and participant sociodemographic factors also appear to influence the effectiveness of AWLs. Findings suggest conclusions differ based on the study methodology used, favoring real-world versus experimental studies. Future research should consider AWL content/formatting and participant sociodemographic factors as moderators. AWLs appear to be a promising approach for supporting more informed alcohol consumption and should be considered as one component in a comprehensive alcohol control strategy.
Keywords: Alcohol; bottles; health warnings.