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.
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.
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.
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.