Meta-Analysis with Trial Sequential Analysis Confirms the Efficacy of Acupuncture for Neck Pain

Conventional meta-analyses pool results from multiple studies, but run the risk of generating spurious positive conclusions when the number of trials grows gradually — a phenomenon known as inflated type I error. Trial sequential analysis (TSA) applies a rigorous statistical adjustment to control this problem, signaling when the accumulated evidence is sufficiently conclusive. A systematic review published in the Journal of Pain Research is the first to apply TSA to the field of acupuncture for neck pain — and the results withstand the most demanding scrutiny.

What TSA adds to conventional meta-analyses

The analysis included 26 RCTs with 3,520 participants, searched in international databases through October 2024 — with 50% of the studies assessed as low risk of bias. On the primary outcomes of pain and disability versus inert treatment, the cumulative Z curve crossed both the conventional significance boundary and the TSA-adjusted boundary, meaning that the conclusion is robust even against the risk of false positives from data accumulation. In other words: the evidence in favor of acupuncture for neck pain is not a statistical artifact — it is conclusive.

Quality of life also improved significantly with acupuncture versus inert treatment, both in the physical and mental components. Heterogeneity between studies was classified as moderate to high — an expected pattern in acupuncture meta-analyses given that treatment protocols vary between clinics and cultures. Even so, the TSA confirmed that the accumulated sample is sufficient for solid conclusions on the primary outcomes.