Despite wide use in clinical practice, acupuncture remains a controversial treatment for chronic pain. Our objective was to update an individual patient data meta-analysis to determine the effect size of acupuncture for 4 chronic pain conditions. We searched MEDLINE and the Cochrane Central Registry of Controlled Trials randomized trials published up until December 31, 2015. We included randomized trials of acupuncture needling versus either sham acupuncture or no acupuncture control for nonspecific musculoskeletal pain, osteoarthritis, chronic headache, or shoulder pain. Trials were only included if allocation concealment was unambiguously determined to be adequate. Raw data were obtained from study authors and entered into an individual patient data meta-analysis. The main outcome measures were pain and function. An additional 13 trials were identified, with data received for a total of 20,827 patients from 39 trials. Acupuncture was superior to sham as well as no acupuncture control for each pain condition (all P < .001) with differences between groups close to .5 SDs compared with no acupuncture control and close to .2 SDs compared with sham. We also found clear evidence that the effects of acupuncture persist over time with only a small decrease, approximately 15%, in treatment effect at 1 year. In secondary analyses, we found no obvious association between trial outcome and characteristics of acupuncture treatment, but effect sizes of acupuncture were associated with the type of control group, with smaller effects sizes for sham controlled trials that used a penetrating needle for sham, and for trials that had high intensity of intervention in the control arm. We conclude that acupuncture is effective for the treatment of chronic pain, with treatment effects persisting over time. Although factors in addition to the specific effects of needling at correct acupuncture point locations are important contributors to the treatment effect, decreases in pain after acupuncture cannot be explained solely in terms of placebo effects. Variations in the effect size of acupuncture in different trials are driven predominantly by differences in treatments received by the control group rather than by differences in the characteristics of acupuncture treatment.
PERSPECTIVE: Acupuncture is effective for the treatment of chronic musculoskeletal, headache, and osteoarthritis pain. Treatment effects of acupuncture persist over time and cannot be explained solely in terms of placebo effects. Referral for a course of acupuncture treatment is a reasonable option for a patient with chronic pain.
Even after discarding the no-placebo-control trials (which have a much greater effect size than those with sham-acupuncture controls, and are likely to be biased), there seems to be an unexplained small effect (although this is hard to interpret in a clinically meaningful way). I have trouble believing it, though, perhaps betraying my underlying bias.
I'm afraid this meta-analysis doesn't provide enough information to drive clinicians who are skeptical about acupuncture for chronic pain to consider advising patients to try acupuncture. Additional research about identifying patients who are most likely to respond may be needed to lead to clinician behavior change.
It has long puzzled me why neurologists are skeptical about acupuncture, and rely on the chronic administration of medications with their potential for side effects.
This individual patient data meta-analysis looked at the effect of acupuncture on pain and function in four patient groups: nonspecific musculoskeletal pain, osteoarthritis, chronic headache, and shoulder pain. Comparator treatments were either sham acupuncture or nonacupuncture treatment. Acupuncture was effective in all patient groups, with greater differences from control groups for nonacupuncture treatment than sham acupuncture. Benefits persisted over time. Variations in effect size were related more to differences in outcomes for the comparison groups than the acupuncture groups. This study confirms a beneficial effect of acupuncture in the pain conditions included in this meta-analysis, and the effects persist over time.
The methods seem to be of high quality. The individual meta-analysis strengthens the findings that acupuncture has modest benefit in chronic pain with minimal, if any, harms.