Efficacy and safety of electroacupuncture for insomnia: A systematic review and meta-analysis

Background: Electroacupuncture is often used to treat insomnia. Objective: To evaluate the efficacy and safety of electroacupuncture for insomnia. Search strategy: Databases including PubMed, Cochrane Library, Embase, Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang Data and VIP Fulltext e-Journals Database were searched up to January 15, 2023. Inclusion criteria: Randomized clinical trials were included if they compared the clinical efficacy and safety of electroacupuncture with sham acupuncture, no treatment or usual care (UC) and general acupuncture. Data extraction and analysis: The full texts of the studies were reviewed to remove ineligible literature. The extracted data included authors, publication year, diagnostic criteria, sample size, population characteristics, interventions and outcomes. The above steps were performed independently by two reviewers and the data were cross-checked. Stata15.0 software was used to analyze the extracted outcome data. For continuous data (Pittsburgh Sleep Quality Index [PSQI] score and Insomnia Severity Index score), weighted mean difference (WMD) was calculated and 95% confidence interval (CI) was reported when the same scale was applied. For dichotomous variables (clinical response rate and adverse events), a meta-analysis was performed using risk ratio (RR) as the effect indicator. Results: Thirty-one trials with 2226 subjects were included. The meta-analysis suggested that electroacupuncture was more effective in improving insomnia compared with the control group (sham acupuncture, no treatment, UC and general acupuncture) (RR = 1.21; 95% CI: [1.16, 1.27]), significantly reducing the PSQI score in insomnia patients after treatment and at follow-up (WMD = -3.23; 95% CI: [-4.29, -2.17]; P < 0.001). There was no significant difference in the incidence of adverse events between the EA and control groups (sham acupuncture and no treatment or UC. RR = 1.48; 95% CI: [0.91, 2.40]; P = 0.117). In addition, the regression results revealed that receiving electroacupuncture for seven to nine weeks provided the best efficacy (P < 0.05). Conclusion: Electroacupuncture can significantly promote better sleep quality in insomnia patients and is suitable for the treatment of various types of insomnia. However, the articles included were single-center trials with small sample sizes, and some articles were of poor quality. Therefore, further research is still needed to confirm these findings.