The analgesic benefits of acupuncture may be partially mediated through placebo effects related to the acupuncturist’s behaviour, according to US researchers. The team conducted a three-month randomised clinical trial in patients with knee osteoarthritis to compare the efficacy of traditional Chinese acupuncture (TCA) with sham acupuncture and to examine the effects of acupuncturists’ communication styles. Acupuncturists were trained to interact in one of two communication styles, conveying either high or neutral expectations for the outcome of the treatment. Four hundred and fifty-five patients were randomised to one of three groups, waiting list, high treatment expectation style, or neutral treatment expectation style. Within each style group, participants were further divided into groups that received either TCA or sham acupuncture, twice a week for six weeks. Sham acupuncture was performed at non-acupoints points with shallow needles and minimal stimulation. No statistically significant differences were observed between TCA and sham acupuncture, however both groups had significant reductions in pain scores compared with the waiting list group. The results showed statistically significant differences in pain reduction and satisfaction, favouring the high treatment expectation group, suggesting that acupuncturists’ communication styles have a significant effect on treatment outcomes. (A randomized controlled trial of acupuncture for osteoarthritis of the knee: effects of patient-provider communication. Arthritis Care Res (Hoboken). 2010 Sep;62(9):1229-36).