Herbal medicine (Gegen-decoction) for treating cervical spondylosis: A systematic review and meta-analysis of randomized controlled trials

Introduction: Gegen-decoction (GGD) is a herbal medicine that has long been used to treat cervical pain in East Asia. This systematic review was conducted to summarize and evaluate of the current evidence pertaining to RCTs of GGD for cervical spondylosis. Methods: We systematically searched 10 databases, PubMed; Cochrane Library; EMBASE, CNKI, Airiti Library, CiNii, OASIS, KoreaMed, KMBASE, NDSL until January of 2017. There were no language restrictions for RCTs. Data extraction and risk of bias assessments were performed by two independent reviewers. We assessed the risk of bias using the 'Cochrane risk of bias'. Results: Five RCTs with a total of 454 participants were included in the analysis. The methodological qualities of the RCTs were low in the performance bias domain. The GGD group had positive effects on the response rate compared with the placebo group. (n = 254, RR: 1.19, 95% Cl: 1.08-1.30, P < 0.00001, I-2 = 0%) Conclusion: GGD may be effective in reducing symptoms of patients with cervical spondylotic radiculopathy. However, this study found that there is insufficient evidence supporting the effect of GGD for cervical spondylosis. Therefore, rigorously designed and placebo-controlled trials of GGD should be conducted to provide such evidence.