Using ecological momentary assessment and a portable device to quantify standard tetrahydrocannabinol units for cannabis flower smoking
Timothy J. Trull, Lindsey K. Freeman, Megan N. Fleming, Tayler J. Vebares, Andrea M. Wycoff
Abstract
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: A total of 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 Pro; 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 = -0.10, P = 0.004, 95% CI, [-0.17, -0.03]). Multi-level model (MLM) results indicated the momentary standard THC units (mg THC) were positively associated with momentary subjective intoxication ratings (b = 0.01, P = 0.03, 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.