Impaired driving is an important public health issue, but its prevalence is challenging to monitor. To report the prevalence of alcohol, cannabis, recreational drugs, and sedating medications in injured Canadian drivers, identify demographic and collision factors associated with drug or alcohol use, and compare the prevalence of drug-involved driving in different parts of Canada. This cross-sectional study prospectively obtained blood samples from injured drivers treated in 15 Canadian trauma centers and measured blood levels of tetrahydrocannabinol (THC; the main impairing…
