Effectiveness of acupuncture as adjunctive therapy in osteoarthritis of the knee: a randomized, controlled trial.

BACKGROUND Evidence on the efficacy of acupuncture for reducing the pain and dysfunction of osteoarthritis is equivocal. OBJECTIVE To determine whether acupuncture provides greater pain relief and improved function compared with sham acupuncture or education in patients with osteoarthritis of the knee. DESIGN Randomized, controlled trial. SETTING Two outpatient clinics (an integrative medicine facility and a rheumatology facility) located in academic teaching hospitals and 1 clinical trials facility. PATIENTS 570 patients with osteoarthritis of the knee (mean age [+/-SD], 65.5 +/- 8.4 years). INTERVENTION 23 true acupuncture sessions over 26 weeks. Controls received 6 two-hour sessions over 12 weeks or 23 sham acupuncture sessions over 26 weeks. MEASUREMENTS Primary outcomes were changes in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores at 8 and 26 weeks. Secondary outcomes were patient global assessment, 6-minute walk distance, and physical health scores of the 36-Item Short-Form Health Survey (SF-36). RESULTS Participants in the true acupuncture group experienced greater improvement in WOMAC function scores than the sham acupuncture group at 8 weeks (mean difference, -2.9 [95% CI, -5.0 to -0.8]; P = 0.01) but not in WOMAC pain score (mean difference, -0.5 [CI, -1.2 to 0.2]; P = 0.18) or the patient global assessment (mean difference, 0.16 [CI, -0.02 to 0.34]; P > 0.2). At 26 weeks, the true acupuncture group experienced significantly greater improvement than the sham group in the WOMAC function score (mean difference, -2.5 [CI, -4.7 to -0.4]; P = 0.01), WOMAC pain score (mean difference, -0.87 [CI, -1.58 to -0.16];P = 0.003), and patient global assessment (mean difference, 0.26 [CI, 0.07 to 0.45]; P = 0.02). LIMITATIONS At 26 weeks, 43% of the participants in the education group and 25% in each of the true and sham acupuncture groups were not available for analysis. CONCLUSIONS Acupuncture seems to provide improvement in function and pain relief as an adjunctive therapy for osteoarthritis of the knee when compared with credible sham acupuncture and education control groups.