Being involved in a road accident after consuming alcohol, medication, cannabis or other recreational drugs is far from an exceptional situation.
Indeed, a
pan-Canadian study, published in
Jama Network Open, reveals that substances that can impair abilities were detected in more than half of motorists transported to emergency rooms following a collision in Canada.
Illustration image Pixabay
A team of 22 scientists, including
Marcel Émond and
Éric Mercier, professors at the Faculty of Medicine of Université Laval and researchers at the CHU de Québec - Université Laval Research Center, reached this conclusion after analyzing blood samples taken from 8,328 people who were behind the wheel during a road accident that occurred between January 2019 and June 2023.
Their injuries, ranging from moderate to severe, required transportation to the emergency rooms of the 15 participating hospitals across 8 Canadian provinces.
Within 6 hours of the accident, blood samples for clinical purposes had been taken from these individuals. The remaining blood samples after testing were used for analyses to detect the presence of substances that could affect driving ability.
Five categories of substances were considered: alcohol, cannabis, opioids, stimulants such as cocaine, amphetamines and Ritalin, as well as sedatives like antidepressants, anxiolytics and insomnia medications. "In these last three cases, we are not able to determine whether the individuals had used these products therapeutically or recreationally," specifies Marcel Émond.
The analyses revealed the presence of at least one of these substances in 55% of subjects and the presence of at least 2 substances in 22% of subjects.
The substance classes most frequently detected were sedatives (28%), alcohol (16%; 13% of all subjects were above the 0.08 threshold), cannabis (16%; 3% of all subjects were above the 5 ng THC/ml threshold), stimulants (13%) and opioids (11%).
Alcohol and cannabis are subject to clear legal frameworks and there are many awareness campaigns encouraging people not to drive after consuming them, Professor Émond reminds us. "Our data shows that these efforts must continue."
For most other substances, there is no defined limit not to exceed. The recommendations concerning their use, when used as medications, are very vague regarding driving. "The association our study establishes between road accidents and the presence of certain medications in drivers' blood raises a red flag on this issue," concludes the researcher.