Sham acupuncture techniques are not inert: An overview

Acupuncture (AT) has accumulated an extensive clinical evidence base, yet its efficacy remains controversial, partly because of sham acupuncture in randomized controlled trials testing the specific effects of acupuncture. The aim of this overview is to critically review the assumption that sham acupuncture is inert, examine the methodological implications of sham needle design, and evaluate whether the sham needling points affects clinical outcomes. We argue that sham acupuncture cannot be considered a valid placebo treatment because it activates the somatosensory system through tactile stimulation, which is a component of the mechanism of acupuncture. We also discuss evidence showing that the use of sham-devices in the sham and verum arms of acupuncture trials results in a suboptimal representation of verum acupuncture as practiced clinically. Meanwhile, the location of the points selected for sham acupuncture is highly relevant. Comparisons across multiple clinical conditions show no significant difference between ‘verum acupuncture and sham needling at real acupuncture points’ Sham AT (verum), however sham AT (verum) produces significantly greater pain relief than ‘sham needling at non-acupoints’ Sham AT (sham) in chronic low back pain. The reporting quality of sham needle characteristics has not improved over time, which presents an obstacle to the full understanding of sham interventions. We conclude that sham acupuncture is an active intervention that leads to underestimation of acupuncture efficacy. Researchers should carefully consider control design, adhere to the ACURATE reporting guideline, and interpret the results of sham-controlled trials appropriately.