The effects of acupuncture versus sham/placebo acupuncture for insomnia: A systematic review and meta-analysis of randomized controlled trials

Background: Acupuncture has been found to be an effective treatment for insomnia. but it is not clear whether acupuncture is just a placebo effect. We aimed to compare the efficacy and safety of acupuncture and sham/placebo acupuncture. Methods: We searched the Central Register of Controlled Trials of Medline, EMBASE, and Cochrane from database inception through March 16, 2020 for randomized controlled trials (RCTs) that compared acupuncture therapy with sham/placebo acupuncture or no treatment. Restricted to English language. Cochrane risk of bias tool was used to analyze risk of bias of the included randomized controlled trials (RCT). Data analysis was performed with Review Manager 5.3. Results: A total of 15 studies involving 1108 patients. Meta-analysis results showed that acupuncture therapy was superior to sham/placebo acupuncture in terms of improving Pittsburgh sleep quality index (PSQI), insomnia severity index (ISI), total sleep time (TST), sleep-onset latency (SOL), wake after sleep onset (WASO), sleep efficiency (SE), even during the follow-up period, acupuncture therapy was superior to sham/placebo acupuncture on PSQI. Due to the obvious heterogeneity of the study, (1) for primary outcome (PSQI): subgroup analysis based on the type of acupuncture and placebo acupuncture showed that acupuncture was superior to placebo acupuncture lower PSQI: acupuncture was superior to placebo acupuncture (3RCTs, MD = 7.34, 95% [-8.02, -6.66], I2 = 86%) and minimal acupuncture (5RCTs, MD = 3.29, 95% [-3.95, 2.63], I2 = 53%), Auricular acupressure was superior to placebo acupuncture (1RCT, MD = 4.16, 95% [-6.57, 1.75]), minimal acupuncture was superior to electroacupuncture (2RCTs, MD = 0.70, 95%CI [0.52, 0.87], I2 = 0%), while there was no significant difference between auricular acupressure and minimal acupuncture, between electroacupuncture and placebo acupuncture. trials). (2) for secondary outcome (ISI, TST, WASO, SE, SOL). ISI, the ISI score of minimal acupuncture was lower than that of electroacupuncture (2RCTs, MD = 0.80, 95%CI [0.55, 1.04], I2 = 0), acupuncture was lower placebo acupuncture (1RCT, MD = 7.89, 95%CI [-10.15, -5.63]), There was no significant difference between electroacupuncture and minimal acupuncture. Conclusion: Based on the outcomes included in this study, the efficacy of acupuncture was superior to that of placebo acupuncture in treating insomnia. Types of acupuncture therapy and placebo may underestimate the efficacy of acupuncture in different ways.