RESUMEN
BACKGROUND: The Traditional Chinese Medicine (TCM) Tian Wang Bu Xin Dan (TWBXD) has been used widely for treating insomnia in China. The purpose of this meta-analysis was to evaluate the efficacy and safety of TWBXD in the treatment of insomnia. OBJECTIVE: This study evaluated the efficacy and safety of TWBXD for insomnia. METHODS: We searched seven main databases including PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Chinese Biomedicine Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), and Wan-fang. We identified randomized-controlled trials (RCTs) for insomnia treatment involving TWBXD, TWBXD combined with conventional Western medicine, and conventional Western medicine from their inception to May 2018. The quality of literature was evaluated by Cochrane assessing tool to reduce the risk of bias. Meta-analysis and heterogeneity of results across the trials were performed. RevMan 5.3 was used to synthesize the results. RESULTS: 14 studies involving 1,256 participants were identified in this systematic review. Methodological deficiencies existed in most of the included trials. Few studies described the generation of a random sequence in detail, the concealment of allocation, and the methods of blinding. No placebo was used in treatment. 12 trials compared TWBXD with conventional Western medicine and 2 trials compared TWBXD combined with conventional Western medicine. The results of our meta-analysis showed relative benefits in effective rates in favor of TWBXD (Odds Ratio [OR] 2.71, 95% confidence interval [CI] 1.67 to 4.39, P < 0.00001) and TWBXD combined with conventional Western medicine (OR 5.05, 95% CI 1.58 to 16.12, P=0.006). The Pittsburgh Sleep Quality Index (PSQI) scores showed similar results, which favored TWBXD (Weighted Mean Difference [WMD] -1.82, 95% CI -3.00 to -0.64, P=0.003). Only 5 trials reported adverse events, whereas the other 9 trials did not provide the safety information. CONCLUSION: This review demonstrates that although the effects of TWBXD on insomnia were promising, they need to be interpreted with caution, due to the poor methodological quality and the small number of trials of the included studies. TWBXD seems to be generally safe, but there is insufficient evidence to make conclusions on the safety because fewer studies reported the adverse events. Further studies on a larger scale with more rigorous designs are required to evaluate the role of TWBXD in the insomnia treatment.