Heterogeneities in administration methods among cannabis users by use purpose and state legalization status findings from a nationally representative survey in the United States, 2020.
Different cannabis administration methods have differential impacts on health. This study aimed to describe administration methods among cannabis users in the United States categorized by (1) use purpose and (2) state legalization status. Cross-sectional, probability-based online survey in 2020. All 50 states and Washington DC in the United States. A total of 21 903 adults (18) were recruited from a probability-based online panel to provide nationally representative estimates. Eleven administration methods were grouped into combustion, vaporization, ingestion and topicals. Weighted prevalence was reported among (1) medical-only, recreational-only and dual-purpose users based on self-reported purposes and (2) users in states that legalized both recreational and medical cannabis (RCL states), legalized medical cannabis only and did not legalize cannabis. Among past-year users, the proportions of medical-only, recreational-only and dual-purpose users were 25.55, 43.81 and 30.64%, respectively. The most common primary methods were combustion (42.08%) and topicals (28.65%) for medical purposes and combustion (72.07%) and ingestion (15.05%) for recreational purposes. Dual-purpose users were more likely to report combustion and vaporization but less likely to report ingestion and topicals as primary methods for medical use than medical-only users (P < 0.001) and more likely to report combustion and topicals but less likely to report ingestion as primary methods for recreational use than recreational-only users (P < 0.041). A higher proportion of dual-purpose users (82.82%) used more than one method than medical-only (40.52%) and recreational-only users (63.91%) (P < 0.001). For both medical and recreational purposes, RCL states had the lowest rate of combustion and the highest rates of ingestion and topicals reported as primary methods (P < 0.033). The rate of using more than one administration method did not differ across states (P > 0.05). Cannabis users whose purposes are medical, recreational or both tend to differ in their selected administration methods.