Medical Cannabis Dosing Trajectories of Patients: Evidence From Sales Data.

Purpose: Medical cannabis use is rising with limited high-quality clinical trial data to guide dosing. This study relies on real-world, longitudinal medical cannabis purchase data to provide information on Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) dosing trends for patients with qualifying medical conditions.

Methods: A retrospective study of purchases by 16,727 patients obtaining medical cannabis from dispensaries located in New York between 2016 and 2019, recorded in point-of-sale data. Group-based trajectory modeling was used to identify clusters of patients following similar progressions in dosing of THC and CBD over time. χ² tests were performed to identify which patient characteristics and qualifying medical conditions were associated with membership in each trajectory group.

Findings: Six trajectory groups were identified that described different patterns in the THC and CBD doses that patients purchased over the whole time period. For THC, the majority of patients (62.6%) purchased a steady amount but at different levels: consistently low (4.1 mg) or moderate (7.4 mg). Three groups, representing 22.0% together, exhibited doses that either fluctuate or constantly increase over time (5-20 mg). A final group of patients (15.8%) exhibited constant decrease in dose from 11 to 5 mg. For CBD, the data show similar trajectories, but at the generally higher values (4-16 mg). Patients with chronic pain, neuropathy, and cancer were overrepresented in groups where higher doses of THC were purchased over time. Patients with epilepsy had a higher representation in groups with higher doses of CBD across time.

Implications: Results suggest heterogeneous dosing patterns and trajectories in the use of medical cannabis by patients with different medical conditions.