COMMENTS AND RESPONSES

TO THE EDITOR: Scharf and colleagues (1) reported that the addi-tion of traditional Chinese acupuncture (TCA) was superior to con-servative therapy but not to sham acupuncture for osteoarthritis of the knee. They suggest that “because complete blinding was impos-sible, this study does not allow us to determine whether the observed effectiveness of TCA and sham acupuncture was due to placebo effects, intensity of provider contact, or a physiologic effect of nee-dling. ” However, 2 related points need to be emphasized. First, either placebo effects or “time effects ” might have led to an overestimation of the differences between blinded and unblinded groups coupled with the narrowing of the discernable difference be-tween real and sham acupuncture. For example, participants receiv-ing real or sham acupuncture might experience a stronger placebo effect. Conversely, those receiving only conservative therapy might report worse results because of reduced patient–provider interactio