Efficacy of acupuncture for migraine prophylaxis: a trial sequential meta-analysis

Background Acupuncture is commonly used for migraine prophylaxis; however, evidence of its efficacy was equivocal. Aim We aimed to evaluated the efficacy of acupuncture in migraine prophylaxis and calculated the required information size (RIS) to determine whether further clinical studies are required. Methods We searched Cochrane library, EMBASE and PubMed from inception to April 23th, 2020. Randomized trials that compared acupuncture with conventional drug therapy or sham acupuncture were included. The primary outcome was migraine episodes. Secondary outcomes were responder rate and adverse event. Results Twenty studies (n = 3380) met the inclusion criteria. When it comes to migraine episodes, Acupuncture was superior over sham acupuncture [SMD = - 0.29, 95% CI (- 0.47 to - 0.11),P = 0.002] after treatment, while the difference between acupuncture and prophylactic drugs was not significant [SMD = - 0.21, 95% CI (- 0.42 to 0.00),P = 0.06].Both TSA graphs indicated that more RCTs are needed. As for responder rate, the results after treatment showed that acupuncture was statistically significantly better than sham acupuncture [RR 1.30, 95% CI (1.09-1.55),P = 0.003] as well as conventional drugs [RR 1.24, 95% CI (1.04-1.48),P = 0.01]. Both of their cumulative Z-curves intersected with the trial sequential monitoring boundaries favoring acupuncture. Compared to prophylactic medication, acupuncture can cause less adverse events [RR 0.34, 95% CI (0.14-0.81),P = 0.01]. Conclusion Acupuncture can reduce migraine episodes compared to sham one and can be an alternative and safe prophylactic treatment for conventional drugs therapy, but it should be further verified through more RCTs. Available studies suggested acupuncture was superior to sham acupuncture and conventional drugs in terms of responder rate as verified by TSA.