About 20% of rheumatology patients actively use cannabis, and meta-analysis shows pain improvement

40.4% of rheumatology patients reported ever using cannabis and 15.3% reported current use. Use was highest in fibromyalgia (68.2%) compared to RA/lupus (26%). Cannabis use was associated with significant pain reduction (pooled effect size -1.75, 95% CI: -2.75 to -0.76). However, cannabis users were younger, more often smokers (OR 2.91), more often unemployed (OR 2.40), and had higher baseline pain.

Systematic review and meta-analysis searching databases through June 2020. Metaproportion calculated cannabis use incidence. Standardized mean differences assessed cannabis effects on pain. Inverse-variance method used for pooling.

Cannabis use is common among rheumatology patients and often undisclosed. Clinicians should proactively ask about cannabis use and understand the available evidence on pain effects to guide clinical conversations.

The high prevalence of cannabis use among rheumatology patients, especially fibromyalgia (68%), combined with the significant pain reduction signal, suggests cannabis is already a de facto part of many patients' pain management, whether or not clinicians are aware.

Heterogeneous study designs and cannabis products. Observational data cannot establish causation for pain reduction. Cannabis users had higher baseline pain, introducing confounding. Self-reported outcomes. Small number of studies for some analyses.