Durable effects of acupuncture for tension-type headache: A systematic review and meta-analysis

Background: Acupuncture may be effective in treating tension-type headache (TTH). The durability of its effects after treatment completion remains inconclusive. Methods: We searched multiple databases and references from previous reviews for randomized controlled trials (RCTs) which investigated the effectiveness of acupuncture for TTH. We assessed the methodological quality of RCTs using the Cochrane Risk of Bias 2.0 (RoB 2) tool. Primary outcome was response rate, defined as the proportion of participants who reported at least a 50% reduction in monthly headache days from baseline after completion of treatment. Secondary outcomes included headache days, headache intensity, and analgesic use. Safety outcomes were also evaluated. Results: A total of seven RCTs involving 3,221 participants with frequent episodic and chronic TTH were included. Individuals receiving acupuncture reported a significantly higher response rate versus sham acupuncture (SA) immediately and at 1-6 months after completion of treatment (P<0.05). Compared with SA, post-treatment results of headache days and headache intensity appeared consistent on the whole, showing associations favoring acupuncture. However, no significant reduction in analgesic use was found post-treatment. Acupuncture showed no superiority over physical training or relaxation training in headache days and headache intensity. Moreover, no serious adverse events associated with acupuncture were reported. Conclusion: Limited evidence suggested that acupuncture might provide durable post-treatment effects in the management of frequent episodic and chronic TTH for up to 6 months compared with SA,with no severe treatment-related adverse events reported.