Cannabis Hospitalizations and Mortality Risk Save

Cannabis use disorders (CUD) are associated with adverse health effects, including mental disorders and motor vehicle collision-related injuries. However, little is known about whether CUDs are associated with increased mortality risk.

A retrospective cohort study of over 11.6 million adults in Ontario, Canada (2006 and 2021) looked at mortality rates between individuals with incident hospital-based CUD care and age- and sex-matched general controls. 

The matched analysis included 527 972 individuals, with a mean age of 30 years and  62.5% were female. Overall there were 106 994 with incident CUD. After being followed for 5 years (after hospital-based CUD care) 3.5% died, compared with 0.6% of matched controls. 

Thus hospital-based CUD care patients had nearly a 3 fold (adjusted hazard ratio 2.79; 95% CI, 2.62-2.97) increased risk of death compared to the general population. This included an increased risk of death from suicide (aHR 9.70), trauma (aHR, 4.55), opioid poisoning (aHR, 5.03), other drug poisonings (aHR, 4.56), and lung cancer (aHR, 3.81). 

When compared to Individuals with hospital-based care for CUD, those with hospital-based care for alcohol (aHR, 1.30 [95% CI, 1.26-1.34]), stimulants (aHR, 1.69 [95% CI, 1.62-1.75]), and opioids (aHR, 2.19 [95% CI, 2.10-2.27]) were also at a relatively increased risk of death within 5 years.

These findings suggest important clinical and policy implications, given global trends toward cannabis legalization and market commercialization accompanied by increasing cannabis use and CUDs.