Does prior acupuncture exposure affect perception of blinded real or sham acupuncture?

To determine if acupuncture-exposed and naïve participants differ in their perceptions of real and sham acupuncture under blinded conditions.

The setting was an outpatient clinic at the Colorado School of Traditional Chinese Medicine. Participants were between the ages of 18 and 90 years. Acupuncture-exposed participants had at least five prior acupuncture treatments, with one treatment in the month prior to the study date. Acupuncture-naïve participants had experienced no prior acupuncture treatments. Participants with dementia, cognitive impairment, or neuropathy were excluded. In total, 61 acupuncture-exposed and 59 acupuncture-naïve participants were blindfolded and received either real acupuncture or toothpick sham acupuncture treatment. Following treatment, participants completed a questionnaire rating the realness of the acupuncture and were asked how they made this determination. We used a previously developed scale rating treatments from 1 (definitely real needle) to 5 (definitely imitation needle) to assess outcome.

Perceptions of the real treatment were rated as more real than sham treatments for all participants. Further analysis revealed that prior acupuncture exposure did not influence ratings of real treatments, but exposed participants rated sham treatments as significantly less real than naïve participants.

Acupuncture-naïve and exposed participants both reported different perceptions of real and sham acupuncture using a blindfolded toothpick protocol. This suggests that future trials should carefully monitor participant perceptions of treatments received, even for naïve individuals. Differences between groups further suggest that participants with significant and/or recent exposure to real acupuncture may introduce bias to blinded clinical acupuncture trials.