Effectiveness of Chinese herbal medicine for patients with primary insomnia: A PRISMA-compliant meta-analysis

Traditional medicine is widely used for patients with primary insomnia, but the studies showed inconsistent results. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effectiveness of Chinese herbal medicine (CHM) versus placebo for primary insomnia patients.

The electronic databases including PubMed, EmBase, Cochrane library, and China National Knowledge Infrastructure were searched to identify the RCTs published from inception till July 2018. The summary weighted mean difference (WMD) with its 95% confidence interval (CI) for Pittsburgh sleep quality index (PSQI), sleep onset latency, total sleep duration, Athens insomnia scale (AIS), and sleep efficiency were calculated using random-effects model.

Fifteen RCTs comprising 1500 patients were finally included in the meta-analysis. Overall, patients who received CHM had lower levels of PSQI (WMD: -2.36; 95% CI: -4.02 to -0.70; P = .005), sleep onset latency (WMD: -11.54; 95% CI: -20.55 to -2.54; P = .012), and AIS (WMD: -0.59; 95% CI: -0.97 to -0.22; P = .002) as compared with placebo. Moreover, the summary WMDs of CHM versus placebo were associated with higher total sleep duration (WMD: 0.79; 95% CI: 0.56-1.02; P < .001), and sleep efficiency (WMD: 9.72; 95% CI: 6.49-12.96; P < .001). The treatment effect on PSQI might be affected by publication year, sample size, mean age, percentage male, diagnostic tool, duration of insomnia, treatment duration, and study quality.

The findings of this meta-analysis indicated that CHM could significantly improve the symptoms of insomnia than placebo for patients with primary insomnia.