Acupuncture versus placebo for the treatment of chronic mechanical neck pain: a randomized, controlled trial.

BACKGROUND Despite substantial increases in its popularity and use, the efficacy of acupuncture for chronic mechanical neck pain remains unproved. OBJECTIVE To compare acupuncture and placebo for neck pain. DESIGN A randomized, single-blind, placebo-controlled, parallel-arm trial with 1-year follow-up. SETTING The outpatient departments of 2 major hospitals in the United Kingdom, 1999 to 2001. PATIENTS 135 patients 18 to 80 years of age who had chronic mechanical neck pain. Eleven patients withdrew from treatment, and 124 completed the primary end point. MEASUREMENTS The primary outcome was pain 1 week after treatment, according to a visual analogue scale. Secondary outcomes were pain at other time points, score on the Neck Disability Index and the Short Form-36, and use of analgesic medications. INTERVENTIONS Patients were randomly assigned to receive, over 4 weeks, 8 treatments with acupuncture or with mock transcutaneous electrical stimulation of acupuncture points using a decommissioned electroacupuncture stimulation unit. RESULTS Both groups improved statistically from baseline, and acupuncture and placebo had similar credibility. For the primary outcome (weeks 1 to 5), a statistically significant difference in visual analogue scale score in favor of acupuncture (6.3 mm [95% CI, 1.4 to 11.3 mm]; P = 0.01) was observed between the 2 study groups, after adjustment for baseline pain and other covariates. However, this difference was not clinically significant because it demonstrated only a 12% (CI, 3% to 21%) difference between acupuncture and placebo. Secondary outcomes showed a similar pattern. LIMITATIONS All treatments were provided by 1 practitioner. Although the control was credible, it did not mimic the process of needling. A nonintervention group was not present to control for regression to the mean. CONCLUSIONS Acupuncture reduced neck pain and produced a statistically, but not clinically, significant effect compared with placebo. The beneficial effects of acupuncture for pain may be due to both nonspecific and specific effects.