Chaihu Longgu Muli decoction, a Chinese herbal formula, for the treatment of insomnia: A systematic review and meta-analysis

PURPOSE: To review the literature on the efficacy and safety of Chaihu Longgu Muli decoction (CLMD) for insomnia. METHODS: A systematic literature search was performed for five databases up to May of 2019 to identify randomized control trials involving CLMD for patients with insomnia. The experimental group was CLMD monotherapy or CLMD plus conventional treatment. Comparators were placebo, no treatment, or conventional medicine. The main comparison was CLMD against conventional drugs. The primary outcome was sleep quality (assessed using the Pittsburgh Sleep Quality Index, PSQI). The secondary outcomes were clinical effectiveness rate, total sleep time, and adverse event rate. RevMan 5.3 software was used for meta-analysis with effect estimate presented as relative risk (RR) and mean difference (MD) with 95% confidence interval (CI). RESULTS: A total of 22 studies involving 2029 patients were included. All the included studies presented some risk of bias, especially risks of performance, and detection bias. The main meta-analysis showed that CLMD alone was more effective than conventional medications by reducing PSQI (MD = −2.80, 95% CI [−5.48, −0.13], P = .04), improving the clinical effectiveness rate (RR = 1.23, 95% CI [1.16, 1.31], P < .00001), and prolonging total sleep time (MD = 1.01, 95% CI [0.19, 1.83], P = .002). The adverse event rate in the CLMD group was lower than that of the control group (RR = 0.22, 95% CI [0.09, 0.51], P = .0005). CLMD also improved sleep quality better than conventional medications as an adjunct therapy (P < .05). The funnel plot was symmetrical, representing a low risk of publication bias. CONCLUSION: CLMD presented better efficacy and safety than conventional medications and had the potential to become an alternative to conventional medications for the treatment of insomnia. However, as the included studies showed significant risks of bias, these results will need to be confirmed by future double-blind randomized controlled trials. PROSPERO REGISTRATION NUMBER: CRD42019133103.