Blog
Does legalizing and commercialising cannabis cause more road accidents?
Sep
In a recent study published within the JAMA Network Open Journal, researchers conducted a cross-sectional study to research the impacts of cannabis legalization on traffic injury in Ontario, Canada.
Study: Cannabis-Involved Traffic Injury Emergency Department Visits After Cannabis Legalization and Commercialization. Image Credit: Yarygin/Shutterstock.com
Background
The recent study captured 426 cannabis-related traffic mishaps leading to hospital emergency department (ED) admissions over the past 13 years.
They report a rise of 475.3% in cannabis-involved road injury but emphasize that market commercialization, not legalization, is liable for this four-fold increase.
While this increase is important, the general proportion of road injuries involving recreational use continues to be minuscule and pales compared to the way more prevalent alcohol-involved traffic mishaps.
Impacts of cannabis legalization
Cannabis is a psychoactive drug derived from plants of the genus Cannabaceae. Native to Central and South Asia, this drug has been used for recreational, medicinal, and entheogenic purposes for hundreds of years.
Consumed predominately via smoking, cannabis use, especially recreational, has been mostly legally banned, with hitherto only eight countries legalizing adult recreational cannabis use.
Following Uruguay, Canada became the second country globally to legalize the licensed sale of cannabis for adult recreational consumption on the 17th of October, 2018. Cannabis consumption, nonetheless, results in intoxication symptoms, presenting a direct risk of motorcar collisions, with risk duration depending on dosage and drug acclimatization.
To counter this, the Canadian government imposed limits on blood tetrahydrocannabinol (THC) levels, allowing a maximum of two ng/mL, exceeding which criminal charges could be enforced on intoxicated drivers.
The impacts of cannabis legalization on traffic mishaps remain poorly understood, with only a number of studies investigating the phenomenon. Most of those studies concentrate on america (US) context, with only two studies conducted in Canada.
Results from this research are confounding, with some studies reporting increases in fatal motorcar accidents, while others report no change in baseline vehicle mishap trends following cannabis legalization.
Notably, most data on cannabis-involved road accidents, especially in Canada, overlap with the coronavirus disease 2019 (COVID-19) pandemic, during which vehicle movement was largely restricted.
Subsequently, a necessity exists to check trends in cannabis-involved vehicle collisions before and after legalization while accounting for reductions in accidents overall through the pandemic.
In regards to the study
In the current study, researchers aimed to research population-level changes in traffic injury ED admissions pre- and post-nonmedical cannabis legalization in Ontario, Canada’s most populous province (14.3 million individuals in 2018).
Their repeated cross-sectional study design followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, with data acquired from a database that captured 100% of ED visits.
Researchers included motorcar, cyclist, and pedestrian ED visit data from January 2010 to December 2021, excluding individuals below 16 (legal Canadian driving age). Data was divided into three exposure periods:
“before legalization (January 2010-September 2018), after legalization but with restricted retail stores and cannabis products (hereafter, legalization) (October 2018-March 2020), and after legalization with unlimited retail stores and expanded products (hereafter, commercialization), which overlapped with the COVID-19 pandemic (April 2020-December 2021).”
The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10), was used to discover and classify ED visits that involved cannabis use. Together with alcohol use (the study control condition), cannabis use was coded as “Hospital Stays for Harm Brought on by Substance Use.”
Research compiled additional covariate data comprising neighborhood rurality and income quantile, age, sex, and preexisting mental health or substance abuse histories.
Finally, quasi-Poisson models generated rate ratios (number of people per 100,000 and 1,000 traffic injury ED visits).
Collision time was included as a linear variable and used to create two independent models, one accounting for seasonality alone and the opposite for seasonality and time trends.
Multivariable logistic regressions were used to discover predictors of cannabis-, alcohol-, or each as liable for ED admissions.
Study findings
Between January 2010 and December 2021, 947,604 traffic injury-related ED visits were recorded, 426 (0.04%) of which involved cannabis use. 4 hundred eighteen individuals with cannabis-influenced traffic injuries were identified (eight incidents of the identical individual’s involvement in multiple traffic collision).
Individuals were, on average, 30.6 years (range 18.6 to 42.6) and predominantly male (78.9%). Notably, 33% of people belonged to the bottom income quintile, with poorer neighborhoods having a greater likelihood of study exposure than their more affluent counterparts.
“Essentially the most common explanation for cannabis-involved traffic ED visits was harmful cannabis use (n = 175, 41.1%), followed by acute intoxication (n = 141, 33.1%) and cannabis dependence or withdrawal (n = 41, 9.6%)”
Analyses revealed that over the 13-year study period, cannabis-involved ED admissions increased from 0.18 per 1,000 individuals (2010) to 1.01 in 2021 (a rise of 475.3%). Per capita, ED visitation for cannabis was observed to extend from 0.13 per 100,000 individuals (2010) to 0.54 per 100,000 individuals (2021; 326.6%), while alcohol-involved ED visitation decreased from 5.83 to 4.73 over the identical duration (18.9%).
“After adjusting for season and time trends, the rise in cannabis-involved total traffic injury ED visits was not significant through the restricted legalization period and was reduced in magnitude through the commercialization/COVID-19 period. The time and seasonally adjusted increase (astRR) in substance-involved visits per motorcar traffic injuries through the commercialization/COVID-19 period remained greater for cannabis (astRR, 1.74; 95% CI, 1.03-2.96) than alcohol (astRR, 1.32; 95% CI, 1.14-1.53)”
Conclusions
The current study investigated the impacts of cannabis legalization and business sale for adult recreational use on traffic collision-related ED visits between 2010 and 2021 in Ontario, Canada.
Analyses of the 947,604 traffic injury-related ED visits recorded during that point revealed a four-fold increase in cannabis-related traffic collisions despite Canadian surveys finding no increase in driving following cannabis use within the province before- and after legalization. The identical period saw a 19% reduction in alcohol-related incidents.
Results revealed that young male adults were probably to cause or be involved in cannabis-involved traffic collisions, with lower-income communities at higher risk than their more affluent counterparts.
Despite the alarming increase reported, cannabis use stays a minor contributor to traffic collisions (1.01%) in comparison with 8.79% involving alcohol use.
In summary, this study highlights individuals at the very best risk of cannabis-involved traffic mishaps, which have to be the targets for interventions using a mixture of education and legislative policy to be sure that future cannabis use stays protected, each for users and people exposed to individuals having fun with the results of the weed.
