Note
Author(s) affiliated with: Alcohol & Drug Abuse Institute, University of Washington, School of Public Health, University of Washington,
Harborview Injury Prevention & Research Center, University of Washington
Department of Epidemiology, University of Washington,
Department of Pediatrics, University of Washington,
Department of Pediatrics School of Medicine, University of Washington.
Résumé
In 1999, Washington State voters approved the legalization of medical marijuana. InNovember 2012, Washington voters passed Initiative-502 (I-502), legalizing retail cannabis sales and recreational cannabis use for adults 21 years and older. As with alcohol, the law provides two options for prosecuting suspected impaired drivers: 1) demonstrating impairment through detailed observation notes, field test results, witness observations, or Drug Recognition Expert assessments; and 2) determining the suspect’s blood level for thedrug is above the legal "per se" limit. I-502 established a per se level of 5ng/mL of activedelta-9-tetrahydrocannabinol (hereafter THC) in blood for cannabis-impaired driving. THCis a psychoactive compound in cannabis.The objectives of this study were to examine drivers involved in collisions and/or arrestedfor suspected driving under the influence (DUI), who were investigated by the WashingtonState Patrol and for which blood evidence was collected in order to: describe the trends inTHC involvement over time and in relation to the passage of I-502; to describe theprevalence of THC alone and in combination with alcohol and other potentially intoxicatingdrugs; and to describe the estimated time to blood draw under real world conditions, andexamine the relationship between estimated time to blood draw and the level of THCdetected. Additionally, to provide necessary context, law enforcement and toxicology testingprocedures as well as arrests, state patrol staffing levels, and training over the study periodwere documented.