Prevalence of Self-Reported Adverse Effects to Cannabis by Older Canadians: A Cross-Sectional Analysis.

Background and objective: Despite the increasing use of cannabis by older Canadians, little is known about cannabis safety in this population, particularly in non-clinical settings. The purpose of this study was to describe the self-reported adverse effects experienced by community-dwelling older Canadians who use cannabis.

Methods: Canadians aged 50 years and older completed an online survey regarding their knowledge, perceptions, and experiences with cannabis. Respondents who reported current cannabis use were asked to report any adverse effects experienced in the past year related to their cannabis use. Adverse effects were categorized, and multivariate logistic regressions were performed to assess predictors of adverse effects.

Results: A total of 1615 older adults completed the survey, of whom 503 reported current use of cannabis and were included in this analysis. Adverse effects were reported by 308 participants (61.2%) and included dry mouth (36.2%), feeling high (25.9%), and adverse effects impacting balance (22.1%) and mental alertness (20.3%). Compared with participants aged 50-60 years, those aged 70 years and older had lower odds of reporting any adverse effects (odds ratio (OR) 0.524, 95% confidence interval (CI) 0.303-0.906) or adverse effects impacting mental alertness (OR 0.318, 95% CI 0.172-0.588). Female participants had higher odds of reporting any adverse effect (OR 1.989, 95% CI 1.332-2971) or adverse effects impacting balance (OR 1.930, 95% CI 1.198-3.109).

Conclusions: Adverse effects to cannabis are common amongst community-dwelling older adults. Increased education and guidance regarding adverse effects of cannabis, including the composition and dose of cannabis products, may help increase safe use by this population.