|
Citation
|
Brubacher JR, Chan H, Erdelyi S, Yuan Y, Daoust R, Vaillancourt C, Rowe B, Lee J, Mercier E, Atkinson P, Davis P, Clarke D, Taylor J, Macpherson A, Émond M, Al-Hakim D, Horwood C, Wishart I, Magee K, Rao J, Eppler J. Addiction 2023; ePub(ePub): ePub. |
|
Abstract
|
BACKGROUND AND AIMS: The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations.
DESIGN: Prospective observational study. SETTING: Fifteen Canadian trauma centres between January 2018 and December 2021. Cases Injured drivers (n=6956) who required blood testing as part of routine trauma care. MEASUREMENTS: We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: High THC (THC≥5ng/mL & BAC=0); High Alcohol (BAC≥0.08% & THC=0) and THC/BAC negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership.
FINDINGS: Most injured drivers (70.2%) were THC/BAC negative; 1,274 (18.3%) had THC>0 including 186 (2.7%) in the High THC group; 1161 (16.7%) had BAC>0 including 606 (8.7%) in the high BAC group. Males and drivers <45 years had higher adjusted odds of being in the High THC group (v.s., THC/BAC negative group). Importantly, 4.6% of drivers <19 years old had THC≥5ng/mL and drivers <19 years had higher unadjusted odds of being in the High THC group than drivers aged 45-54 years old. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers, and drivers injured in single-vehicle, nighttime or weekend collisions had higher adjusted odds ratios [aORs] for being in the High Alcohol group (v.s., THC/BAC negative). Drivers aged <35 or ≥ 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the High THC group (v.s., High BAC group).
CONCLUSIONS: In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single vehicle, nighttime, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions but are more strongly associated with cannabis-related collisions. FUNDING: This study received funding from Health Canada, CIHR, Ministries of Transportation of Alberta and Ontario and Saskatchewan Government Insurance.
Keywords: Cannabis impaired driving; Ethanol impaired driving
Language: en |