REVIEW ARTICLE Acupuncture for Chronic Pain Individual Patient Data Meta-analysis

Background: Although acupuncture is widely used for chronic pain, there remains considerable controversy as to its value.We aimed to determine the effect size of acu-puncture for 4 chronic pain conditions: back and neck pain, osteoarthritis, chronic headache, and shoulder pain. Methods: We conducted a systematic review to iden-tify randomized controlled trials (RCTs) of acupunc-ture for chronic pain in which allocation concealment was determined unambiguously to be adequate. Indi-vidual patient data meta-analyses were conducted using data from 29 of 31 eligible RCTs, with a total of 17 922 patients analyzed. Results: In the primary analysis, including all eligible RCTs, acupuncture was superior to both sham and no-acupuncture control for each pain condition (P .001 for all comparisons). After exclusion of an outlying set of RCTs that strongly favored acupuncture, the effect sizes were similar across pain conditions. Patients receiving acupuncture had less pain, with scores that were 0.23 (95%CI, 0.13-0.33), 0.16 (95%CI, 0.07-0.25), and 0.15 (95 % CI, 0.07-0.24) SDs lower than sham controls for back and neck pain, osteoarthritis, and chronic head-ache, respectively; the effect sizes in comparison to no-acupuncture controlswere 0.55 (95%CI, 0.51-0.58), 0.57 (95 % CI, 0.50-0.64), and 0.42 (95 % CI, 0.37-0.46) SDs. These results were robust to a variety of sensitivity analy-ses, including those related to publication bias. Conclusions: Acupuncture is effective for the treat-ment of chronic pain and is therefore a reasonable refer-ral option. Significant differences between true and sham acupuncture indicate that acupuncture ismore than a pla-cebo. However, these differences are relatively modest, suggesting that factors in addition to the specific effects of needling are important contributors to the therapeu-tic effects of acupuncture