Current evidence on acupuncture from sham needle studies

Objectives : There has been a considerable debate about how to best control for placebo effects in clinical trials of acupuncture. Recently several sham needles were developed and validated. This study aimed at summarising the validation studies of these needles and evaluating the outcomes of the randomised controlled trials (RCTs) using them. Methods : Computerised literature searches were performed using 'acupuncture' AND 'placebo OR sham' with a limitation of the results to RCTs in Medline via PubMed and the Cochrane Library. Only formally validated sham needle controlled studies were included. Data were extracted regarding study design, condition, sample size, credibility testing, intervention and outcomes. Methodological quality was assessed using a modified Jadad scale. Results : Three validated sham needles by Streitberger, Park, and Fink, were identified. Acupuncture's effectiveness for various conditions was tested using these needles in 12 RCTs. Real acupuncture was superior to sham acupuncture for rotator cuff tendonitis and hypertension. No significant differences between real acupuncture and sham acupuncture emerged for chemotherapy-related nausea and vomiting, postoperative nausea and vomiting, menstrually related migraine, acute stroke rehabilitation, chronic/episodic tension-type headache, neutrophil respiratory burst in healthy volunteers, alcohol withdrawal symptoms and chronic poststroke leg spasticity. Conclusions : The new sham devices have been adequately validated and may be useful tools for investigating specific research question. In spite of the sham needle's limits, the results of RCTs using such devices tend to suggest that the clinical effects of acupuncture are largely due to a placebo response.