Objectives: There is controversy as to whether or not acupuncture is more effective than placebo. To help clarify this debate, we synthesized the evidence gathered from systematic reviews on the pooled data of high-quality randomized controlled trials comparing acupuncture to sham acupuncture for chronic pain.
Method: Systematic reviews of acupuncture for the most commonly occurring forms of chronic pain (back, knee, and head) published between 2003 and 2008 were sourced from Ovid databases: Medline, Allied and Complementary Medicine database, Cochrane Library and Web of Science during December 2008. Eight systematic reviews with meta-analyses of pooled data were eligible for inclusion. Data were extracted for short- and longer-term outcomes for the most commonly occurring forms of pain. Two independent reviewers assessed methodological quality.
Results: For short-term outcomes, acupuncture showed significant superiority over sham for back pain, knee pain, and headache. For longer-term outcomes (6 to12 months), acupuncture was significantly more effective for knee pain and tension-type headache but inconsistent for back pain (one positive and one inconclusive). In general, effect sizes (standardized mean differences) were found to be relatively small.
Discussion: The accumulating evidence from recent reviews suggests that acupuncture is more than a placebo for commonly occurring chronic pain conditions. If this conclusion is correct, then we ask the question: is it now time to shift research priorities away from asking placebo-related questions and shift toward asking more practical questions about whether the overall benefit is clinically meaningful and cost-effective?