Background and Aims: Cannabis use is associated with several adverse health effects. However, little is known about the cannabis-attributable burden of disease. This study quantified the age-, sex- and adverse health effect-specific cannabis-attributable (1) mortality, (2) years of life lost due to premature mortality (YLLs), (3) years of life lost due to disability (YLDs) and (4) disability-adjusted life years (DALYs) in Canada in 2012.
Design: Epidemiological modeling.
Setting: Canada.
Participants: Canadians aged >= 15 years in 2012.
Measurements: Using comparative risk assessment methodology, cannabis-attributable fractions were computed using Canadian exposure data and risk relations from large studies or meta-analyses. Outcome data were obtained from Canadian databases and the World Health Organization. The 95% confidence intervals (CIs) were computed using Monte Carlo methodology.
Findings: Cannabis use was estimated to have caused 287 deaths (95% CI = 108, 609), 10 533 YLLs (95% CI = 4760, 20 833), 55 813 YLDs (95% CI = 38 175, 74 094) and 66 346 DALYs (95% CI = 47 785, 87 207), based on causal impacts on cannabis use disorders, schizophrenia, lung cancer and road traffic injuries. Cannabis-attributable burden of disease was highest among young people, and males accounted for twice the burden than females. Cannabis use disorders were the most important single cause of the cannabis-attributable burden of disease.
Conclusions: The cannabis-attributable burden of disease in Canada in 2012 included 55 813 years of life lost due to disability, caused mainly by cannabis use disorders. Although the cannabis-attributable burden of disease was substantial, it was much lower compared with other commonly used legal and illegal substances. Moreover, the evidence base for cannabis-attributable harms was smaller.