Medical cannabis use by rheumatology patients in routine clinical care: results from The Ontario Best Practices Research Initiative.

Medical cannabis is often used to alleviate common symptoms in patients with chronic conditions. With cannabis legalisation in Canada and easier access, it is important that rheumatologists understand its potential impact on their practice. Among patients attending rheumatology clinics in Ontario we assessed: the prevalence of medical cannabis use; symptoms treated; rheumatologists' perceptions. Eight rheumatology clinics recruited consecutive adult patients in a 3-part medical cannabis survey: the first completed by rheumatologists; the second by all patients; the third by medical cannabis users. Student's t-test and Chi-square test were used to compare medical cannabis users to never users. 799 patients participated, 163 (20.4%) currently using medical cannabis or within <2 years and 636 never users; most had rheumatoid arthritis (37.8%) or osteoarthritis (34.0%). Compared to never users, current/past-users were younger; more likely to be taking opioids/anti-depressants, have psychiatric/gastrointestinal disorders, and have used recreational cannabis (p<0.05); had higher physician (2.9 vs. 2.1) and patient (6.0 vs. 4.2) global scores, and pain (6.2 vs. 4.7) (p<0.0001). Pain (95.5%), sleeping (82.3%) and anxiety (58.9%) were the most commonly treated symptoms; 78.2% of current/past-users reported medical cannabis was at least somewhat effective. Most rheumatologists reported being uncomfortable to authorise medical cannabis, primarily due to lack of evidence, knowledge, and product standardisation. Medical cannabis use among rheumatology patients in Ontario was two-fold higher than that reported for the general population of similar age. Use was associated with more severe disease, pain, and prior recreational use. Reported lack of research, knowledge, and product standardisation were barriers for rheumatologist use authorisation.