Association between legalization of recreational cannabis and fatal motor vehicle collisions in the United States: an ecologic study.
Journal
CMAJ open
ISSN: 2291-0026
Titre abrégé: CMAJ Open
Pays: Canada
ID NLM: 101620603
Informations de publication
Date de publication:
Historique:
entrez:
18
3
2021
pubmed:
19
3
2021
medline:
20
7
2021
Statut:
epublish
Résumé
With 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. We 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. After 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). Recreational 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.
Sections du résumé
BACKGROUND
With 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.
METHODS
We 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.
RESULTS
After 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).
INTERPRETATION
Recreational 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.
Identifiants
pubmed: 33731424
pii: 9/1/E233
doi: 10.9778/cmajo.20200155
pmc: PMC8096392
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
E233-E241Subventions
Organisme : CIHR
ID : SHI-155407
Pays : Canada
Informations de copyright
© 2021 Joule Inc. or its licensors.
Déclaration de conflit d'intérêts
Competing interests: None declared.
Références
Clin Chem. 2013 Mar;59(3):478-92
pubmed: 23220273
Accid Anal Prev. 2005 Jan;37(1):149-61
pubmed: 15607286
Addiction. 2019 May;114(5):847-856
pubmed: 30719794
Accid Anal Prev. 2019 Nov;132:105284
pubmed: 31518764
Am J Epidemiol. 2003 Jan 15;157(2):131-40
pubmed: 12522020
Accid Anal Prev. 2018 Sep;118:57-65
pubmed: 29885927
Inj Epidemiol. 2019 Feb 4;6(1):3
pubmed: 30714081
JAMA Intern Med. 2020 Aug 1;180(8):1061-1068
pubmed: 32568378
Health Policy. 2018 Mar;122(3):205-209
pubmed: 29429644
JAMA Intern Med. 2020 Aug 1;180(8):1119-1120
pubmed: 32568359
Addiction. 2020 Oct;115(10):1944-1953
pubmed: 32141142
Public Health. 2020 Jan;178:7-14
pubmed: 31600630