There is conflicting evidence on the efficacy of traditional Chinese acupuncture (TCA), and the role of placebo effects elicited by acupuncturists' behavior has not been elucidated. We conducted a 3-month randomized clinical trial in patients with knee osteoarthritis to compare the efficacy of TCA with sham acupuncture and to examine the effects of acupuncturists' communication styles.
Acupuncturists were trained to interact in 1 of 2 communication styles: high or neutral expectations. Patients were randomized to 1 of 3 style groups, waiting list, high, or neutral, and nested within style, TCA or sham acupuncture twice a week over 6 weeks. Sham acupuncture was performed in nonmeridian points with shallow needles and minimal stimulation. Primary outcome measures were Joint-Specific Multidimensional Assessment of Pain (J-MAP), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and satisfaction scores.
Patients (n = 455) received treatment (TCA or sham) and 72 controls were included. No statistically significant differences were observed between TCA or sham acupuncture, but both groups had significant reductions in J-MAP (-1.1, -1.0, and -0.1, respectively; P < 0.001) and WOMAC pain (-13.7, -14, and -1.7, respectively; P < 0.001) compared with the waiting group. Statistically significant differences were observed in J-MAP pain reduction and satisfaction, favoring the high expectations group. In the TCA and sham groups, 52% and 43%, respectively, thought they had received TCA (κ = 0.05), suggesting successful blinding.
TCA was not superior to sham acupuncture. However, acupuncturists' styles had significant effects on pain reduction and satisfaction, suggesting that the analgesic benefits of acupuncture can be partially mediated through placebo effects related to the acupuncturist's behavior.