Cannabis use and self-reported collisions in a representative sample of adult drivers.

Problem: This study examines the relationships between collision involvement and several measures of cannabis use, including driving after using cannabis, among drivers, based on a population survey of Ontario adults in 2002 and 2003.

Method: Logistic regression analyses examined self-reported collision involvement in the last 12 months by lifetime use of cannabis, past year use of cannabis, and past year driving after using cannabis, while controlling for demographic characteristics.

Results: We found that the odds of reporting collision involvement was significantly higher among cannabis users, and among those who reported driving after cannabis use. Some evidence for a dose-response relationship was seen as well.

Discussion: Cannabis users and people who report driving after cannabis use are also more likely to report being involved in a collision in the past year. These observations suggest that collision prevention efforts could be aimed at these groups. Additional work to determine the causal pathways involved in the relationships observed here is needed.

Impact On Industry: None.