Although acupuncture has been widely used to treat a variety of pain conditions, convincing scientific evidence for its efficacy is lacking. Earlier randomised controlled trials attempted to follow a double-blind, placebo-controlled model. This approach has encountered many problems such as the virtual impossibility of blinding the acupuncturist and the uncertainties inherent in choosing control acupuncture points. The objective of this review is to assess if acupuncture is an effective treatment for chronic pain. In addition, a number of key methodological issues that arise in the controlled evaluation of acupuncture will be discussed.
This review is based on the result of previous reviews, meta-analyses and consensus conference. The search was performed with MEDLINE (from 1966), EMBASE (from 1980) and Cochrane library (1999, volume 1). Only randomised trials of acupuncture (involved needling) for subjects with chronic pain published in English were included.
Basic science research has demonstrated convincingly that at least in the context of acute pain, acupuncture's effects are related to the release of a variety of natural opioids. Acupuncture has been shown to be effective for postoperative dental pain. There are reasonable studies showing relief of pain with acupuncture on diverse pain conditions such as menstrual cramps, tennis elbow, low back pain and fibromyalgia. This suggests that acupuncture may have a more general effect on pain. However, there are also studies which provide equivocal results because of design, sample size and other factors. The issue is further complicated by inherent difficulties in the use of appropriate controls, such as placebo and sham acupuncture groups.
As most of the studies were of poor methodological quality, there is a need for further high quality randomised controlled trials. Future studies should also have larger sample sizes, use a valid acupuncture treatment, and have both a short-term and long-term follow-up.