Controlled trial of Japanese acupuncture for chronic myofascial neck pain: assessment of specific and nonspecific effects of treatment.

OBJECTIVE: This article examines the specific and nonspecific effects of Japanese acupuncture on chronic myofascial neck pain in a randomized single-blind trial.

DESIGN: Forty-six patients were randomly assigned to receive relevant acupuncture, irrelevant acupuncture, or no-acupuncture control treatment consisting of nonsteroidal anti-inflammatory medication. The two acupuncture groups underwent comparable light shallow needling. The irrelevant acupuncture group received acupuncture at specific sites not relevant for cervical pain.

OUTCOME MEASURES: The study measures included the McGill Pain Questionnaire-Short Form (SF-MPQ), the Short-Form Health Survey (SF-36), the Symptom Checklist 90-Revised (SCL-90-R), medication diary, and physiologic measures. The factors examined as predictors of outcome pain ratings were experience with, beliefs about, and knowledge of acupuncture before treatment; perceived efficacy, credibility, and logic of acupuncture; perceived competence of the acupuncturist; and painfulness of acupuncture.

RESULTS: No differences were found among the three groups at baseline, except that the relevant acupuncture group reported having had more previous acupuncture treatments. No significant differences in terms of perceived credibility or perceived effectiveness of treatment were found between the two acupuncture groups. The relevant acupuncture group had significantly greater pre-/posttreatment differences in pain than the irrelevant acupuncture and control groups (p < .05). The nonspecific effects of confidence in the acupuncturist, willingness to try any treatment, mood, and physiologic effect of needling were not predictive of treatment outcome, whereas confidence in the treatment and past experiences with acupuncture did correlate significantly with a decrease in pain.

CONCLUSIONS: Relevant acupuncture with heat contributes to modest pain reduction in persons with myofascial neck pain. Previous experience with and confidence in treatment help to predict benefit. Measurement of nonspecific effects of alternative therapy is recommended in future clinical trials.