A systematic review and meta-analysis of self-reported exposure to cannabis advertising and its association with cannabis use and intentions.

Background And Aims: Global changes in cannabis legislation have raised concerns about the potential impact of cannabis advertising on cannabis use and intentions to use. This systematic review and meta-analysis evaluated the relationship between self-reported exposure to cannabis advertising across various media platforms and self-reported cannabis use and use intentions. Design: Systematic review and meta-analysis of eligible quantitative studies using random-effects models. Setting: All included studies were conducted in the United States or Canada. Participants: Participants ranged in age from 11 to 65 + years across 21 included studies. Measurements: Studies measured self-reported exposure to cannabis-related advertising and either cannabis use or intentions to use cannabis. Three types of exposure were examined: [1] general cannabis advertising (a composite measure including billboards, storefront/sidewalk, magazines, social media, and other types of advertising avenues), [2] internet/social media advertising, and [3] storefront/sidewalk advertising. Findings: A total of 2588 records were identified through database searches (PubMed, Scopus, and PsycINFO; January 2024). After title and abstract screening, 45 underwent full text review; of these, 21 studies met inclusion criteria. Most were cross-sectional (86%, n = 18), and three were longitudinal. Ten cross-sectional studies were eligible for meta-analysis, which found a statistically significant association between cannabis advertising exposure and cannabis use (adjusted odds ratio [aOR] = 1.77, 95% confidence interval [CI] [1.32, 2.30]). Statistically significant heterogeneity was found (Q [11] = 22.73, P < 0.05, I(2) = 42.3%) and therefore, based on methodological comparability, three additional meta-analyses were conducted by exposure type. General cannabis advertising (3 studies) exposure was statistically significantly associated with cannabis use (aOR = 1.67, 95% CI [1.27, 2.21]); internet/social media advertising (5 studies) also showed a statistically significant association (aOR = 3.38, 95% CI [1.07, 10.66]); exposure to storefront/sidewalk advertising (3 studies) was not statistically significantly associated with cannabis use (aOR = 1.25, 95% CI [0.95, 1.66]). Across studies, methodological quality was mostly good (48%) or satisfactory (43%), with 10% rated as unsatisfactory. Conclusion: There appears to be a generally positive association between exposure to cannabis advertising and cannabis use, with a consistent positive relationship observed between advertising exposure and intentions to use.