Acupuncture Does Help for Chronic Pain
Acupuncture provides more relief from various types of chronic pain than does usual care and should be considered a valid therapeutic option, the authors of a meta-analysis concluded.
For back and neck pain, osteoarthritis, and chronic headache, pain scores among patients treated with acupuncture were 0.23 (95% CI 0.13 to 0.33), 0.16 (95% CI 0.07 to 0.25) and 0.15 (95% CI 0.07 to 0.24) standard deviations below the scores for patients receiving sham acupuncture (P<0.001 for all), according to Andrew J. Vickers, DPhil, of Memorial Sloan-Kettering Cancer Center in New York City, and colleagues.
But effect sizes were even larger when acupuncture was compared with no acupuncture, with scores of 0.55 (95% CI 0.51 to 0.58), 0.57 (95% CI 0.50 to 0.64), and 0.42 (95% CI 0.37 to 0.46) standard deviations lower (P<0.001 for all), the researchers reported online in Archives of Internal Medicine.
Acupuncture is recognized as having certain physiologic effects that can contribute to pain relief, but no plausible mechanism has been identified that could lead to long-term benefits for chronic pain, with the result that the treatment remains "highly controversial," according to the researchers.
Many controlled studies of acupuncture for pain have been published, but quality has been inconsistent and reliability has been questioned.
To provide more clarity about the effects of acupuncture on pain, Vickers and colleagues conducted an individual patient data meta-analysis based exclusively on high quality randomized trials.
Included trials required pain of at least a month's duration, with the primary endpoint being assessed at least a month after acupuncture treatment began.
The researchers were able to acquire the original raw data for 29 studies that included 17,922 patients.
To explain the clinical significance of the effect sizes found in the meta-analyses, they noted that a typical pain score in a clinical trial might be 60 on a 100-point scale.
If the standard deviation was assumed to be 25, scores after treatment could be 30 for true acupuncture, 35 for sham acupuncture, and 43 for no acupuncture, they estimated.
Another way of looking at this would be that if response was categorized as a decrease in pain of 50%, response rates would be 50% for true acupuncture compared with 42.5% and 30% for sham acupuncture and no acupuncture, respectively.
"The average effect, as expressed in the meta-analytic estimate of approximately 0.5 [standard deviations], is of clear clinical relevance whether considered either as a standardized difference or when converted back to a pain scale," Vickers and colleagues stated.
They noted that there was significant heterogeneity in a number of the analyses, particularly in the control groups of the various studies.
In some trials, for example, patients in the usual-care control groups were permitted to have rescue analgesics only, while in other studies there were exercise and physical therapy programs.
Moreover, in the sham acupuncture trials, different approaches were permitted, such as using nonpenetrating needles and using non-needle methods such as inactive electrical stimulation.
Other limitations of the meta-analysis included the possibility of bias when acupuncture was compared with no acupuncture and the use of different endpoints in some trials.
Nonetheless, the authors stated that their findings should be considered "both clinically and scientifically important."
They noted that many clinicians would be unwilling to refer a patient for acupuncture if the effects derived only from the nonspecific belief on the part of the patient that the treatment would help.
But the finding that true acupuncture had significantly greater effects than the sham procedure indicates that the effects of the procedure do extend beyond placebo, they observed.
This is "of major importance for clinical practice," meaning that acupuncture should be considered "a reasonable referral option for patients with chronic pain," they stated.
In an invited commentary accompanying the meta-analysis, Andrew L. Avins, MD, of Kaiser-Permanente in Oakland, Calif., argued that the benefits indeed were primarily those associated with the placebo effect, because the pain relief was so much greater when acupuncture was compared with usual care than when compared with the sham procedure.
But whether that should mean acupuncture has no value for patients, largely because of uncertainty as to its mechanisms of action, is a crucial concern, he pointed out.
"The ultimate question is: does this intervention work (or, more completely, do its benefits outweigh its risks and justify its cost)?" Avins wrote.
For acupuncture, the current meta-analysis offers "some robust evidence" that acupuncture does provide greater chronic pain relief than usual care, mechanisms of effect aside.
"Perhaps a more productive strategy at this point would be to provide whatever benefits we can for our patients, while we continue to explore more carefully all mechanisms of healing," Avins concluded.
Funding for this work was provided by the National Center for Complementary and Alternative Medicine, the Samueli Institute, and the U.K. National Institute for Health Research.
Authors and editorialist all reported no financial disclosures.
