A Canadian study investigating cannabis related traffic accidents found injury rates increased sharply after the substance was legalised and commercialised for personal use.
In October 2018, Canada became one of the first countries to legalise the recreational use of cannabis on a restricted basis, later expanding access by allowing the sale of edible cannabis products and concentrates.
Researchers from The Ottawa Hospital, Bruyère Research Institute and the Institute for Clinical Evaluative Sciences analysed data from 947,604 emergency department visits between 2010 and 2021 for traffic injuries in Ontario, Canada, publishing their results in JAMA Network Open.
They found traffic injuries involving cannabis increased by 94% following legalisation, compared to pre-legalisation levels.
Then following commercialisation, traffic injuries increased 223%, compared to pre-legalisation.
Lead author Dr Daniel Myran, a fellow at The Ottawa Hospital and Bruyère Research Institute, says: “Our findings highlight a concerning increase in cannabis-involvement in traffic-injury emergency visits over time, with even sharper spikes following the phases of legalization and commercialization.”
“The study highlights the need for enhanced prevention efforts, including targeted education and policy measures,” he says.
The Canadian research found alcohol-related injuries did not increase over the study timeframe.
The analysis excluded data for children younger than 16, the minimum legal age for driving.
The findings show higher rates of cannabis related emergency department visits for traffic injuries among young adult males from lower income neighbourhoods.
The authors note higher rates of testing may explain some of the observed increase, but is unlikely to account for all of the uptick.
They add that given the decline in driving and mobility due to COVID-19, further study is needed to fully understand the impact of cannabis legalisation on road safety.