ArticleCMAJ open
Association between legalization of recreational cannabis and fatal motor vehicle collisions in the United States: an ecologic study.
Article in CMAJ open. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
18 citing papers in PubMed, 3 syntheses or guidelines pooled it.
- Road hazard: a systematic review of traffic injuries following recreational cannabis legalization.CJEM · 2024Pooled it
- Effects of Cannabis Legalization on Road Safety: A Literature Review.International journal of environmental research and public health · 2023Pooled it
- The clouded debate: A systematic review of comparative longitudinal studies examining the impact of recreational cannabis legalization on key public health outcomes.Frontiers in psychiatry · 2022Pooled it
- Impact of partial cannabis legalisation in Luxembourg: An interdisciplinary perspective.Drug and alcohol dependence reports · 2026Article
- Pediatric Trauma Trends Before and After Recreational Cannabis Legalization in Nevada: A Retrospective Repeated Cross-Sectional Study.Children (Basel, Switzerland) · 2026Article
- Impact of naturalistic cannabis use on lateral control and speed: A driving simulator study.Traffic injury prevention · 2025Article
- Cannabis retail store density and county-level mortality from injury in the state of Washington from 2009-2020.The American journal of drug and alcohol abuse · 2025Article
- Review
- Examining the effect of cannabis cues on cannabis demand in sleep, driving, and typical drug-use contexts.Drug and alcohol dependence · 2024Article
- Review
- Review
- Developments and Changes in Primary Public Health Outcome Indicators Associated with the Legalization of Non-Medical Cannabis Use and Supply in Canada (2018): A Comprehensive Overview.International journal of mental health and addiction · 2022Article
- The association between cannabis and codeine use: a nationally representative cross-sectional study in Canada.Journal of cannabis research · 2022Article
- Attentional function and inhibitory control in different substance use disorders.Psychiatry research · 2022Article
- Changes in Traffic Crash Rates After Legalization of Marijuana: Results by Crash Severity.Journal of studies on alcohol and drugs · 2022Article
- A comprehensive breath test that confirms recent use of inhaled cannabis within the impairment window.Scientific reports · 2021Article
- Article
- Impaired driving and legalization of recreational cannabis.CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors.
Funding
Abstract
backgroundWith the recent legalization of recreational cannabis in Canada, cannabis-impaired driving is an important public safety concern. Our aim was to examine the association between recreational cannabis legalization and fatal motor vehicle collisions using data from the United States, which present a timely natural experiment of cannabis legalization.
methodsWe conducted an ecologic study using the number of fatal motor vehicle collisions and the associated number of deaths for US jurisdictions with legalized recreational cannabis (2007-2018) retrieved from the US Fatality Analysis Reporting System. We examined jurisdiction-specific rates of fatal motor vehicle collisions and associated deaths before and after recreational cannabis legalization using Poisson regression and meta-analyzed estimates across jurisdictions using DerSimonian and Laird random-effects models.
resultsAfter adjustment for calendar year, legalization was associated with increases in rates of fatal motor vehicle collisions (incidence rate ratio [IRR] 1.15, 95% confidence interval [CI] 1.06-1.26) and associated deaths (IRR 1.16, 95% CI 1.06-1.27). Differences between the first 12 months after legalization relative to subsequent months were inconclusive for rates of fatal motor vehicle collisions (IRR 0.92, 95% CI 0.84-1.02) and associated deaths (IRR 0.92, 95% CI 0.84-1.01).
interpretationRecreational cannabis legalization in the US was associated with a relative increased risk of fatal motor vehicle collisions of 15% and a relative increase in associated deaths of 16%, with no conclusive difference between the first and subsequent years after legalization. These findings raise concern that there could be a similar increase in fatal motor vehicle collisions and associated deaths in Canada following recreational cannabis legalization.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.