Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel.
Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
Eur J Pain. 2021 Feb;25(2):359-374. doi: 10.1002/ejp.1675. Epub 2020 Nov 9.
Although studied in a few randomized controlled trials, the efficacy of medical cannabis (MC) for chronic pain remains controversial. Using an alternative approach, this multicentre, questionnaire-based prospective cohort was aimed to assess the long-term effects of MC on chronic pain of various aetiologies and to identify predictors for MC treatment success.
Patients with chronic pain, licensed to use MC in Israel, reported weekly average pain intensity (primary outcome) and related symptoms before and at 1, 3, 6, 9 and 12 months following MC treatment initiation. A general linear model was used to assess outcomes and identify predictors for treatment success (≥30% reduction in pain intensity).
A total of 1,045 patients completed the baseline questionnaires and initiated MC treatment, and 551 completed the 12-month follow-up. At 1 year, average pain intensity declined from baseline by 20% [-1.97 points (95%CI = -2.13 to -1.81; p < 0.001)]. All other parameters improved by 10%-30% (p < 0.001). A significant decrease of 42% [reduction of 27 mg; (95%CI = -34.89 to 18.56, p < 0.001)] from baseline in morphine equivalent daily dosage of opioids was also observed. Reported adverse effects were common but mostly non-serious. Presence of normal to long sleep duration, lower body mass index and lower depression score predicted relatively higher treatment success, whereas presence of neuropathic pain predicted the opposite.
This prospective study provides further evidence for the effects of MC on chronic pain and related symptoms, demonstrating an overall mild-to-modest long-term improvement of the tested measures and identifying possible predictors for treatment success.
尽管有一些随机对照试验对医用大麻（MC）治疗慢性疼痛的疗效进行了研究，但仍存在争议。本多中心、基于问卷的前瞻性队列研究采用了一种替代方法，旨在评估 MC 治疗各种病因慢性疼痛的长期效果，并确定 MC 治疗成功的预测因素。
以色列获得 MC 使用许可证的慢性疼痛患者在开始 MC 治疗前和治疗后第 1、3、6、9 和 12 个月每周报告平均疼痛强度（主要结局）和相关症状。使用线性混合模型评估结局并确定治疗成功（疼痛强度降低≥30%）的预测因素。
共有 1045 名患者完成了基线问卷并开始接受 MC 治疗，其中 551 名患者完成了 12 个月的随访。1 年后，平均疼痛强度从基线下降了 20%[-1.97 分（95%CI=-2.13 至-1.81；p<0.001)]。其他所有参数均改善了 10%-30%（p<0.001）。阿片类药物等效日剂量也显著下降了 42%[减少 27 毫克；（95%CI=-34.89 至 18.56，p<0.001)]。报告的不良反应很常见，但大多是非严重的。睡眠时长正常或较长、体重指数较低和抑郁评分较低预测治疗成功率相对较高，而神经病理性疼痛则相反。
这项前瞻性研究进一步提供了 MC 治疗慢性疼痛及其相关症状的疗效证据，表明测试指标总体上有轻度至中度的长期改善，并确定了治疗成功的可能预测因素。
