Developing and validating a sham acupuncture needle

Objectives: To develop a sham needle device and test its credibility as a control for acupuncture when used in a randomised controlled trial of myofascial trigger point needling in patients with whiplash associated pain. Methods: Sham needles were developed by blunting true acupuncture needles. Whiplash injured patients (< 16 weeks duration) were randomly allocated to receive either true acupuncture or the placebo sham needle control. The true and sham needling interventions were delivered using the same standardised procedure. Patients were informed that they would receive either real or placebo needles, and asked (i) to state which treatment they believed they had received (treatment belief); (ii) to complete the four item Borkovec and Nau self-assessment credibility scale. Results were compared between groups and the analysis explored whether a patient's previous experience of acupuncture was related to their treatment belief. Other outcomes of the study will be reported elsewhere. Results: 20 patients received the true acupuncture and 21 received the sham. There was no significant difference between the treatment beliefs of the two groups (chi(2) = 1.51; p > 0.2) nor in the mean item scores on the Borkovec and Nau credibility scale (t test, p values ranged from 0.38 to 0.87). Of the patients in the sham acupuncture group who had previous experience of acupuncture, none recorded receiving the sham intervention. Conclusion: Within the context of this pilot study, the sham acupuncture intervention was found to be a credible control for acupuncture. This supports its use in a planned, definitive, randomised controlled trial on a similar whiplash injured population.