The Impact of Cannabis Legalization on Traffic Injuries: A Closer Look at Ontario, Canada

Cannabis legalization has been a subject of debate and discussion for years, with proponents highlighting potential economic benefits and proponents raising concerns about public safety. One of the major concerns surrounding cannabis legalization has been its potential impact on traffic injuries. How does the availability of cannabis products and retail stores affect traffic injury rates? A recent study conducted in Ontario, Canada, sheds light on this question, offering valuable insights into the evolving landscape of cannabis-involved traffic injuries.

The Ontario Study

The study, a repeated cross-sectional analysis, examined changes in cannabis- and alcohol-involved traffic injury emergency department (ED) visits in Ontario, Canada, over three distinct time periods. These time periods were defined as:

• Pre Legalization (January 2010 – September 2018): This phase covered the years leading up to cannabis legalization in Canada.
• Legalization with Product and Retail Store Restrictions (October 2018 – February 2020): This phase marked the initial stages of cannabis legalization, characterized by limited product availability and retail store options.
• Commercialization with New Products and Expanded Stores (March 2020 – December 2021): This phase coincided with the COVID-19 pandemic and saw increased availability of cannabis products and retail stores.

The study included all individuals aged 16 and older eligible for Ontario's Universal Health Coverage.

Key Findings

During the study period, there were a total of 947,604 traffic injury ED visits, of which:

• 426 (0.04%) were documented to have cannabis involvement.
• 7,564 (0.8%) had documented alcohol involvement.

Among those with documented cannabis involvement:

• 78.9% were male.
• 25.6% were aged 16 to 21 years (with an average age at the visit being 30.6 years).
• 27.0% had a history of an ED visit or hospitalization for substance use in the two years before their traffic injury ED visit.

The study revealed some striking trends:

• Annual rates of cannabis-involved traffic injury ED visits increased by a staggering 475.3% over the study period.
• In contrast, alcohol-involved traffic injury ED visits increased by only 9.4% during the same period.

Legalization and Traffic Injuries

The findings also suggest that cannabis legalization had a significant impact on traffic injuries:

• Legalization with restrictions was associated with a 94% increase in the quarterly rate of cannabis involvement in traffic injury ED visits relative to the pre legalization period.
• The subsequent phase of commercialization, which coincided with the COVID-19 pandemic, saw an even greater increase of 223% in cannabis involvement rates.

Risk Factors

The study identified several risk factors associated with cannabis involvement during traffic injury ED visits:

• Male sex (adjusted odds ratio [aOR], 3.38).
• Living in the lowest-income neighborhood (aOR, 1.92).
• Being aged 19 to 21 years (aOR, 4.67).
• Having a prior cannabis-related ED visit (aOR, 8.03).

Conclusion

In conclusion, this cross-sectional study conducted in Ontario, Canada, highlights the significant increases in cannabis involvement in ED visits for traffic injuries over time. These increases appear to have accelerated following nonmedical cannabis commercialization. While the frequency of such visits remains relatively rare, they may reflect broader changes in cannabis-impaired driving.

These findings underscore the importance of greater prevention efforts, including targeted education and policy measures, in regions with legal cannabis. The study serves as a crucial resource for policymakers and advocates alike, offering insights into the complex interplay between cannabis legalization and public safety on the roads. As cannabis legalization continues to evolve worldwide, studies like this provide valuable guidance for mitigating potential risks and ensuring the safety of all road users.