title: Acupuncture for chronic pain: individual patient data meta-analysis.
abstract: 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 acupuncture for 4 chronic pain conditions: back and neck pain, osteoarthritis, chronic headache, and shoulder pain.
  
  
  METHODS
  We conducted a systematic review to identify randomized controlled trials (RCTs) of acupuncture for chronic pain in which allocation concealment was determined unambiguously to be adequate. Individual 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 headache, respectively; the effect sizes in comparison to no-acupuncture controls were 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 analyses, including those related to publication bias.
  
  
  CONCLUSIONS
  Acupuncture is effective for the treatment of chronic pain and is therefore a reasonable referral option. Significant differences between true and sham acupuncture indicate that acupuncture is more than a placebo. However, these differences are relatively modest, suggesting that factors in addition to the specific effects of needling are important contributors to the therapeutic effects of acupuncture.
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA. vickersa@mskcc.org
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Vickers
authors.forename: Angel M
authors.initials: AM
authors.lastname: Cronin
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Maschino
authors.forename: George
authors.initials: G
authors.lastname: Lewith
authors.forename: Hugh
authors.initials: H
authors.lastname: MacPherson
authors.forename: Nadine E
authors.initials: NE
authors.lastname: Foster
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Sherman
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Witt
authors.forename: Klaus
authors.initials: K
authors.lastname: Linde
mesh_terms: D015670:Acupuncture Therapy / Q000379:methods*; D059350:Chronic Pain / Q000628:therapy*; D006801:Humans; D010147:Pain Measurement; D016896:Treatment Outcome