The design and reporting of sham acupuncture and its association with the efficacy in acupuncture randomized controlled trials for migraine

This systematic review and meta-analysis represents an important milestone in understanding the methodological quality of acupuncture clinical trials for migraine. The investigators analyzed 46 randomized controlled trials that used sham acupuncture as a control group, applying the SHARE (SHam Acupuncture REporting) checklist to evaluate reporting quality. Migraine, the second leading cause of disability worldwide and affecting more than 1 billion people, represents a significant public health problem in which acupuncture has shown efficacy as a complementary therapy. However, the heterogeneity in therapeutic results has been attributed to the diversity of sham acupuncture protocols used as control.

The methodology involved a systematic search of eight databases (four in English and four in Chinese) from inception through May 2024, focusing on trials comparing true acupuncture with sham acupuncture in patients with migraine. The authors extracted data on study characteristics, central elements of the intervention based on the SHARE checklist, and efficacy outcomes. Central intervention elements were identified, including needle types, manipulation techniques, frequency, duration, and application points. The results revealed significant deficiencies in reporting quality.

Only 43% of SHARE checklist items were adequately reported, with particular gaps in patient information (8.7% of studies), practitioner training (13.04%), and clinician-patient communication (17.39%). Studies published in English showed better reporting quality compared with those in Chinese, especially in methodological aspects such as blinding procedures and practitioner training. The meta-analysis of 14 studies showed that true acupuncture had a higher response rate than sham (RR 1.52, 95% CI 1.26-1.85), with substantial heterogeneity (I²=70.1%). Crucially, meta-regression analysis identified that specific manipulation elements significantly affected efficacy: basic manipulation techniques (β=-0.76), frequency (β=-0.34), number of manipulations (β=-0.34), timing of manipulation (β=-0.34), and duration per session (β=-0.34).

These findings suggest that differences in manipulation techniques between true and sham acupuncture may confound the assessment of acupuncture-specific efficacy. The study has important clinical implications. First, it demonstrates the urgent need for standardization of sham acupuncture protocols, especially minimizing unnecessary stimuli such as excessive manipulation in penetrating sham controls. Second, it underscores the importance of more detailed reporting following guidelines such as SHARE to improve transparency and reproducibility of research.

Third, it suggests that future trials should carefully consider manipulation elements when designing sham controls. Limitations include the small number of studies included in the meta-analysis, restricting statistical power, and dependence on published information that may not fully reflect actual practice. In addition, only two studies used non-penetrating sham acupuncture, limiting subgroup analyses. The study contributes significantly to the field by objectively quantifying central elements that affect acupuncture efficacy, differing from previous qualitative approaches.

The inclusion of studies in Chinese and English reduces linguistic publication bias. The authors recommend rigorous adoption of reporting guidelines such as SHARE, minimization of manipulation in penetrating sham controls, and conduct of larger multicenter studies to validate these findings and establish standardized sham acupuncture protocols.