Clinical Profiles of Concurrent Cannabis Use in Chronic Pain: A CHOIR Study.

OBJECTIVE: Despite evidence of the analgesic benefits of cannabis, there remains a relative scarcity of research on the short- and long-term effects of cannabis use in individuals with chronic pain.

DESIGN: The current study is a secondary analysis of clinical data from the Collaborative Health Outcomes Information Registry (CHOIR).

SETTING: Data were drawn from a cohort of patients of a multidisciplinary tertiary care pain clinic.

SUBJECTS: The study sample consisted of data from 7,026 new patient visits from CHOIR; of these, 1,668 patients with a follow-up time point within 180 days were included in a longitudinal analysis.

METHODS: Clinical data were analyzed to characterize cross-sectional differences in pain and indicators of psychological and physical function according to self-reported, concurrent cannabis use. Additionally, a propensity score-weighted longitudinal analysis was conducted, examining cannabis use as a predictor of changes in clinical variables across time.

RESULTS: Cross-sectional analyses suggested significantly poorer sleep and significantly higher intensities of pain, emotional distress, and physical and social dysfunction in patients reporting ongoing cannabis use; however, these differences were relatively small in magnitude. However, no differences between cannabis users and nonusers in terms of longitudinal changes in clinical variables were noted.

DISCUSSION: Our results are among the first to examine concurrent cannabis use as a prognostic variable regarding trajectories of pain-related variables in tertiary care. Future studies may benefit from examining the effect of cannabis initiation, concurrent medication use, and specific aspects of cannabis use (dose, duration of use, or cannabis type) on clinical outcomes.