Brubacher JR, et al. - By conducting a responsibility analysis, researchers examined drivers injured in motor vehicle collisions who tested positive for Δ-9-tetrahydrocannabinol (THC) or other drugs vs those who tested negative, regarding their contribution to the crash. For this prospective case-control study, toxicology results on 3,005 injured drivers and police reports on 2,318 were obtained. In 14.4% of drivers, alcohol was detected, THC in 8.3%, other drugs in 8.9%, and sedating medications in 19.8%. Findings revealed no raised crash risk in drivers with THC<5ng/mL and a statistically non-significant raised risk of crash responsibility in drivers with THC≥5ng/mL in this sample of non-fatally injured motor vehicle drivers in British Columbia, Canada. In drivers with BAC≥0.08%, other recreational drugs detected, or sedating medications detected, there was significantly higher risk of crash responsibility.