Dangguijagyag-san for primary dysmenorrhea A PRISMA-compliant systematic review and meta-analysis of randomized-controlled trials

Background: This systematic review and meta-analysis aim to assess the effectiveness of Dangguijagyag-san (DJS) for primary dysmenorrhea (PD) and to update the previous reviews. Methods: We searched for randomized controlled trials (RCTs) of DJS for PD from inception to April 2019. The search databases were the PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Oriental Medicine Advanced Searching Integrated System, Korean Traditional Knowledge Portal, Korean Medical Database, National Digital Science Library, and the China National Knowledge Infrastructure. The selection of studies, the extraction of data, and the quality assessment with risk of bias tool were performed by 2 authors independently. To analyze the data, the meta-analysis was conducted and qualitative analysis was also performed. Results: Total 2766 studies were identified, and 14 RCTs were enrolled in this review. According to the type of interventions, the analysis was performed in 4 groups. In comparison to western medication, DJS showed a higher total effective rate (TER) (RR 1.16, 95% CI 1.08-1.24) and a higher effect in reducing the pain (MD = -0.86, 95% CI -1.56--0.16). Compared with placebo, DJS was superior to placebo in reducing pain (MD = -1.1, 95% CI -2.04 --0.16) and also in reducing the consumption of the rescue medication during menstrual period (MD = -2.3, 95% CI -3.58--1.02). Compared with other herbal medicines, the subgroup analysis showed that DJS applied with PD of differentiated patterns had a higher total effective rate (TER) (RR 1.21, 95% CI 1.03-1.43, P=.02). DJS with moxibustion as an adjuvant therapy was also more effective than western medication (RR 1.47, 95% CI 1.23-1.76). Conclusion: DJS may be effective for the treatment of PD. However, the quality of the evidence is relatively low, so larger-scale and well-designed RCTs are needed to confirm the effects of DJS. Systematic review registration: PROSPERO registration number is CRD42019130768.