Cannabis Legalization, Commercialization Linked to Traffic Injuries

THURSDAY, Sept. 7, 2023 (HealthDay News) -- Legalization and commercialization of cannabis in Canada were associated with an increase in cannabis-involved traffic injury emergency department (ED) visits, according to a study published online Sept. 6 in JAMA Network Open.

Daniel T. Myran, M.D., M.P.H., from the University of Ottawa in Ontario, Canada, and colleagues examined changes in the number and characteristics of cannabis-involved traffic injury ED visits in individuals ages 16 years and older in a repeated cross-sectional study. Changes were assessed during prelegalization (January 2010 to September 2018), legalization with product and retail store restrictions (October 2018 to February 2020), and commercialization, which coincided with COVID-19 (March 2020 to December 2021). There were 947,604 traffic injury ED visits overall; 0.04 and 0.8 percent had documented cannabis and alcohol involvement, respectively.

The researchers found that of the 418 individuals with documented cannabis involvement during an ED visit, 78.9 percent were male, 25.6 percent were aged 16 to 21 years, and 27.0 percent had an ED visit or hospitalization for substance use in the preceding two years. During the study period, the annual rates of cannabis-involved traffic injury increased 475.3 percent (0.18 to 1.01 visits per 1,000 total motor vehicle crashes in 2010 and 2021, respectively). Alcohol-involved traffic injury ED visits increased by 9.4 percent during the same period (8.03 to 8.79 per 1,000 traffic injury ED visits from 2010 to 2021). An increase in the quarterly rate of cannabis involvement in traffic injury ED visits was seen during legalization with restrictions and commercialization periods (adjusted rate ratios, 1.94 and 3.23, respectively) versus prelegalization. Male sex, living in the lowest-income neighborhood, being aged 19 to 21 years, and having a prior cannabis-related ED visit were all positively and significantly associated with cannabis-involved traffic injury ED visits.

"Our findings highlight a concerning increase in cannabis-involvement in traffic-injury emergency visits over time, with even sharper spikes following the phases of legalization and commercialization," Myran said in a statement.

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