Background/Purpose: Fibromyalgia (FM) is characterized by a constellation of symptoms that are often poorly responsive to current treatments, and patients are increasingly turning to medical cannabis (MC) as a strategy to improve pain and well-being. To date, little is known about the factors that may contribute to the perceived benefits of medical cannabis in patients with FM. Given that negative affect (i.e., anxiety, depression) and sleep problems contribute to heightened pain intensity and poor well-being, improvements in these variables might indirectly contribute to MC treatment benefits. Factors contributing to continuation of MC treatment, a surrogate for treatment satisfaction, are also largely unknown. The objectives of the present analyses were: 1) to examine whether changes in negative affect and sleep problems contributed to changes in pain intensity and well-being following initiation of MC; 2) to examine the factors contributing to MC treatment continuation.

Methods: Patients included in this study were part of a prospective, observational, non-comparative registry of adult patients who initiated MC under the supervision of a physician between 2015 and 2018 in Quebec, Canada. Sociodemographic and clinical characteristics were recorded at baseline. MC treatment characteristics (MC products, routes, doses) and symptom variables were assessed during in-clinic visits at baseline and every three months for a period of one year.

Results: Of the 2068 chronic non-cancer pain patients enrolled in this registry, 308 (14.9 %) had FM. The FM sample included 87 % women (mean age: 52.3 ± 12.9 years) and most patients (54.3 %) were using a combination of THC and CBD. Results revealed significant improvements in pain intensity and well-being following initiation of MC (both ps < .05). A multilevel mediation analysis subsequently revealed that reductions in pain intensity were mediated by reductions in negative affect (p < .001) and sleep problems (p < .001). Improvements in well-being were mediated by reductions in negative affect (p < .001) and pain intensity (p < .05). MC was continued by 74%, 58.8%, 39.6%, and 23.1% of FM patients at the 3, 6, 9, and 12-month time points, respectively. The likelihood of treatment discontinuation was higher among patients with higher levels of pain and negative affect (both ps < .05), but was unrelated to the degree of improvement in these symptoms over the course of MC treatment (all ps > .05).

Conclusion: Our findings suggest that reductions in negative affect and sleep problems are important contributors to improvements in pain intensity and well-being among FM patients using MC. Discontinuation of MC was more common among those with higher levels of pain and negative affect but was not related to symptom improvement. These findings are a move towards precision medicine in MC recommendations for treatment of FM.

« Back to ACR Convergence 2021

ACR Meeting Abstracts - https://acrabstracts.org/abstract/factors-associated-with-pain-reduction-and-improved-well-being-among-fibromyalgia-patients-using-medical-cannabis/