[OA] The Annual Cannabis Holiday and Fatal Traffic Crashes
Background: Cannabis use has been linked to impaired driving and fatal accidents. Prior evidence suggests the potential for population-wide effects of the annual cannabis celebration on April 20th ("4/20"), but evidence to date is limited.
Methods: We used data from the Fatal Analysis Reporting System for the years 1975-2016 to estimate the impact of "4/20" on drivers involved in fatal traffic crashes occurring between 1620h and 2359h in the United States. We compared the effects of 4/20 to those for other major holidays, and evaluated whether the impact of "4/20" had changed in recent years.
Results: Between 1992-2016 "4/20" was associated with an increase in the number of drivers involved in fatal crashes (Incidence rate ratio [IRR]: 1.12, 95% CI 0.97 to 1.28) relative to control days one week before and after, but not when compared with control days one and two weeks before and after (IRR 1.05, 95% CI 0.92 to 1.28) or all days of the year (IRR 0.98, 95% CI 0.88 to 1.10). Across all years we found little evidence to distinguish excess drivers involved in fatal crashes on 4/20 from routine daily variations.
Conclusions: There is little evidence to suggest population-wide effects of the annual cannabis holiday on the number of drivers involved in fatal traffic crashes.
[OA] Harper S, Palayew A. The Annual Cannabis Holiday and Fatal Traffic Crashes. 2019. https://osf.io/tzcsy/
Re: Staples JA, Redelmeier DA. The April 20 Cannabis Celebration and Fatal Traffic Crashes in the United States. JAMA Intern Med. 2018;178(4):569–572. April 20 and Fatal Traffic Crashes in the United States