Question: The use of cannabis and/or alcohol is usually discussed as increasing the risk for motor vehicle crash. What is the role of cannabis and alcohol in cycling related crash risk?
Answer: One recent study found: “Approximately 15% of cyclists reported using cannabis just prior to the crash, and 14.5% reported using alcohol. Cannabis use identified by blood testing or self-report in the case period and by self-report in the control period yielded a crash risk of 2.38 (1.04–5.43); however, when self-report was used for both the case and control periods the estimate was 0.40 (0.12–1.27). Alcohol use, as measure either in blood or self-report, was associated with an odds ratio of 4.00 (95% CI: 1.64–9.78); results were similar when alcohol was measured by self-report only.” (Asbridge M. et al. Cycling-related crash risk and the role of cannabis and alcohol: a case-crossover study. 2014 Preventive Med 66:80-86)