Increased identification of cannabis use among drivers involved in motor vehicle collisions using an expanded cannabis inventory

Objectives: The objectives of this study were to implement and examine the potential capture rate of a novel instrument, the Expanded Cannabis Inventory, in a population of emergency department (ED) patients presenting after motor vehicle collisions (MVC). Methods: Study participants who presented to the ED after MVC were recruited from three hospitals in cannabis-legal states (Denver, CO; Portland, OR; and Sacramento, CA). Research assistants (RAs) administered the Expanded Cannabis Inventory, which includes a wide variety of products that have become readily available in states where cannabis is legal, in addition to assessments related to patient demographic characteristics, general health, cannabis attitudes, and dependency measures. RAs also obtained blood samples for delta-9-THC and metabolites. Results: Among 692 participants who provided responses to questions about cannabis use, 292 (42%) reported past-year use. Seventy-eight (27%) of those identified as using cannabis were only captured due to items in the expanded instrument. These patients were more likely to be White and were more likely to perceive daily use to be of high risk. Fewer had Cannabis Use Disorder Inventory Test (CUDIT) scores consistent with hazardous cannabis use. However, more of the patients only captured by the expanded instrument had high measured blood levels of delta-9-THC on samples obtained in the ED. Conclusions: Changing cannabis use patterns must be reflected in our measurements for clinical practice, research, and surveillance. Instruments that are the current standard in clinical practice capture limited data and may no longer perform well enough to identify a complete cohort or to provide insight into the health behaviors of patients.