Before people jump on board a “new” treatment for chronic pain, such as laser acupuncture, they should review both sides of the issue before spending any time and money to treat their problem. According to Acupuncture Today, laser acupuncture uses a type of low-heat laser that does not produce heat or cut open the skin in lieu of the fine needles that acupuncturists use. The high-tech laser version has been tested and used in practice in the United States since the 1980s. Although it has touted as a safer alternative to needle acupuncture, a recent study that was published in the Journal of American Medical Association (JAMA) showed that neither laser nor needle acupuncture are better than sham laser acupuncture (placebo) for pain or function.
The 12-week Australian study had 282 volunteers who were ages 50 or older and have chronic knee pain. The volunteers were divided into four groups: control (n=71), laser (n=71), needle (n=70), and sham (n=70). The treatment was administered by “family physician acupuncturists.” The control group received no treatment and were unaware that the experiment is happening. Researchers followed up with the volunteers right after and a year later after the study. They found no significant difference in outcome of knee pain and function between the laser and needle group and the sham group. Compared with the control group, needled and lasered volunteers had “moderately improvements in pain” after 12 weeks, but the improvements were not maintained for a year. The sham group was compared with the control group, and the similar results were found.
The JAMA study may conflict with one systematic review that was published in Rheumatology in 2007 that reviewed 13 randomized controlled trials on acupuncture’s effect on knee pain. The researchers from the Peninsula Medical School in the U.K. found that “acupuncture that meets specified criteria for adequacy” is superior to the sham version for treating chronic knee pain, “both in the short-term and the long-term.”
Currently, there are few quality studies — particularly randomized controlled trials and systematic reviews — that examine the effectiveness or efficacy of acupuncture for knee pain; however, existing evidence on other types of muscle and joint pain often show that the treatment tends to perform a little better or no better than sham acupuncture. For example, the current Cochrane review on its effectiveness for shoulder pain states that the evidence cannot “support or refute the use of acupuncture for shoulder pain,” but for short-term relief, there appears to be some evidence. The Cochrane review also showed insignificant benefit between “real” and sham acupuncture for long-term low back pain relief.
Most of the confusion and conflict in most acupuncture studies is that they tend to be heavy on research bias, such as having a small sample population, observation and publication bias, and poor experimental setup. This can make interpretations difficult for scientists, clinicians, and the public to understand whether a treatment has quality efficacy or effectiveness.
In an editorial published in Elsevier journal, Dr. Kevin Mullane, Ph.D., and Dr. Mike Williams, Ph.D., discussed different types of biases that are common in research. These include, but not exclusively, bias through ignorance (e.g.favoring or opposing a proposition on the basis of a lack of evidence against or for it), bias by design (favoring an experiment setup that supports a hypothesis rather than refuting it), and bias by misrepresentation (e.g. exaggerating or undermining a phenomenon). Therefore, those who read research literature must be able to identify the magnitude of bias before accepting or refuting the findings of any research.
For example, in the JAMA study, did the researcher have a bias in the sample population by choosing only those who are 50-years-old and older? Would this sample population carry over to most of the general population in Australia or most of the world? Would this apply to running or CrossFit athletes in their twenties and thirties?
In the 2007 systematic review of acupuncture in knee pain, did the researchers ignore studies that showed negative results of the treatment and favor those studies that have positive outcomes? Do more current studies and reviews support or refute this review’s results and conclusions? These are a few of the questions that need to be asked when reading any research papers.
So going back to the original topic of acupuncture and knee pain, current evidence based on recent studies are quite mixed with laser and needle versions when compared with the sham version. The verdict is still a vast gray sea that most researchers and clinicians cannot readily agree. When the biases of such research are removed, maybe the true efficacy and effectiveness of this treatment on any kind of pain can be revealed. And perhaps the question that should be asked is not whether acupuncture or other interventions “work” or not, but what exactly is the nature of chronic (knee) pain. By understanding the problem itself first, then researchers and clinicians can find a better intervention to treat the problem. Meanwhile, it is still a buyer-beware market for the public.
By Nick Ng