Medical Marijuana & Me (M3): Designing Measures of Medical Marijuana Dose in an Observational Study

Abstract

Measuring marijuana exposure represents one of the biggest challenges in marijuana-related outcomes research. The challenge mainly emerges from the significant variability in medical marijuana (MMJ) use characteristics on both the product level, including inter-product and intra-product composition variability and possibility of using multiple consumption modes, and the patient level, including variations in use patterns, frequency and intensity of use, and routes of administration. While MMJ-related observational research still mainly relies on self-reported MMJ exposure, there remains a lack of validated and reliable exposure measures and a lack of standardized dose units, necessitating the development of such measures. In the Medical Marijuana & Me (M3) study, a new combined cohort and cross-sectional study aiming to assess a multitude of MMJ-related outcomes among MMJ patients in Florida, we developed a set of new comprehensive measures to quantify MMJ use by assessing the specific modes of consumption, doses, frequency, and patterns of MMJ use. After reviewing the literature for existing MMJ measures, a multidisciplinary team of MMJ certifying physicians, pharmacists, researchers, MMJ patients, and dispensary personnel designed and developed a questionnaire covering a wide range of MMJ products, including flower, vape cartridges, concentrates for smoking, topical products, tinctures, oral concentrates, edible products, and others. MMJ dose and use are assessed via a nine-item MMJ use measure for each MMJ product participants use that gauges modes and routes of administration, frequency of use (per day, per week, per month), amount of consumed products, tetrahydrocannabinol and cannabidiol concentrations and ratios, and potency. For specific consumption modes (e.g., smoking and vaping), additional questions (e.g., number of inhalation seconds) were included to ensure a comprehensive approach of exposure measurement. Visual prompts such as product example photos were also included to enhance participant engagement and ease. We pilot-tested the questionnaires on twenty current MMJ patients in Florida, who provided feedback to improve the measures’ relatability and enhance accuracy in capturing their MMJ exposure. Some of the key challenges we encountered were measuring the “amount” of solid and liquid concentrates, and difficulty in determining dose of vape cartridges due to inconsistencies in THC concentration between nearly identical cartridges. The nine-item MMJ use questionnaire developed for M3 offers a framework for MMJ exposure quantification in current and future observational MMJ-outcomes research. Analyses resulting from M3 data will add to the sparse literature on MMJ dose measures and assist in validating measures similar to the measure developed for M3.