LAUSR

AIMS To evaluate the feasibility and validity of a new method of quantifying cannabis flower use, integrating the amount of cannabis flower smoked and the potency of the cannabis flower. DESIGN Ecological momentary assessment (EMA) for 14 days. SETTING Participants' daily lives in Columbia, Missouri, USA. PARTICIPANTS 50 community participants, who were regular cannabis flower smokers (48% female). MEASUREMENTS Momentary subjective intoxication ratings following cannabis flower smoking; momentary quantity of cannabis flower smoked; potency of cannabis flower smoked in terms of percentage of tetrahydrocannabinol [THC] concentration assessed with a portable device, the Purpl ProTM ; and time since finished smoking. FINDINGS Participants completed our field testing of their cannabis flower (96.2%) and were compliant with our 2-week EMA protocol (73% for random prompts and 91% for morning reports). Momentary subjective intoxication ratings trended down as a function of time since smoking (r = -.10, p = .004, 95% confidence interval (CI) [-.17, -.03]). Multi-level model (MLM) results indicated the momentary standard THC units (mgTHC) were positively associated with momentary subjective intoxication ratings (b = 0.01, p = .03, 95% CI [0.01, 0.012]). CONCLUSIONS There is evidence to support the feasibility and initial validity of a new method of quantifying cannabis flower use into standard tetrahydrocannabinol units. Researchers investigating the effects of cannabis flower use on a range of outcomes (e.g., neurobehavioral effects, emotional sequelae, and driving impairment) as well as in clinical treatment trials might adopt this method to provide estimates of cannabis flower use.