Reprint of: Efficacy, tolerability, and safety of non-pharmacological therapies for chronic pain: An umbrella review on various CAM approaches

Background: Complementary and alternative medicine (CAM) therapies may be used as a non-pharmacological approach to chronic pain management. While hundreds of trials about individual CAM modality have been conducted, a comprehensive overview of their results is currently lacking for pain clinicians and researchers. Aim: This umbrella review synthesized the quality of meta-analytic evidence supporting the efficacy, tolerability and safety of CAM therapies for the management of chronic pain. Materials & methods: MEDLINE, EMBASE, CINAHL, and CENTRAL were searched from October 1991 to November 2016. Reviews of clinical trials (randomized and non-randomized) with meta-analysis investigating the utility of any CAM modality for chronic pain were eligible. Pain relief post-intervention was the main outcome and secondary outcomes included patients' adherence and incidence of adverse effects during CAM protocol. Results: Twenty-six reviews (207 clinical trials,> 12,000 participants) about 18 CAM modalities, falling under natural products, mind and body practices or other complementary health approaches were included. Inhaled cannabis, graded motor imagery, and Compound Kushen injection (a form of Chinese medicine) were found the most efficient (with moderate-to-high effect sizes and low heterogeneity) and tolerable (>= 80% of adherence to study protocols) for chronic pain relief. When reported, adverse effects related to these CAM were minor. Conclusion: Although several CAM were found effective for chronic pain relief, it remains unclear when these modalities are a reasonable choice against or in conjunction with mainstream treatments. In that sense, future research with a clear emphasis on concurrent evaluation of CAM overall efficacy and patient adherence/tolerance is needed.