Sham on You; Acupuncture, Placebo Effect and Sham Controls

This morning I came across NY Times report of yet another acupuncture study trying to determine the efficacy of acupuncture.  This time, the meta-analysis of studies and statistical analysis of data examined the efficacy of acupuncture for chronic pain compared with sham or placebo.

http://well.blogs.nytimes.com/2012/09/11/acupuncture-provides-true-pain-relief-in-study.

Even though acupuncture is part of a centuries old medical system, questions about its efficacy have long been commonplace. Are those who swear by acupuncture's benefits experiencing true relief or the placebo effect?

“This has been a controversial subject for a long time,” said Dr. Andrew J. Vickers,  the lead author of the study and attending research methodologist at Memorial Sloan-Kettering Cancer Center in New York . “But when you try to answer the question the right way, as we did, you get very clear answers.

The researchers, who published their results in  Archives of Internal Medicine, found that acupuncture outperformed sham treatments and standard care when used by people suffering from osteoarthritis, migraines and chronic back, neck and shoulder pain.Dr. Vickers and a team of scientists from around the world pooled years of acupuncture data.  Rather than averaging the results or conclusions from years of previous studies, a common but less rigorous form of meta-analysis, Dr. Vickers and his colleagues first selected 29 randomized studies of acupuncture that they determined to be of high quality. The meta-analysis included studies that compared acupuncture with usual care, like over-the-counter pain relievers and other standard medicines. It also included studies that used sham acupuncture treatments, in which needles were inserted only superficially, for example, or in which patients in control groups were treated with needles that covertly retracted into handles.

Then they contacted the authors to obtain their raw data, which they scrutinized and pooled for further analysis. This helped them correct for statistical and methodological problems with the previous studies, allowing them to reach more precise and reliable conclusions about whether acupuncture actually works.  This process took over six years and over 30-40 people involved in the project analyzing data from over 18,000 patients.  The study was funded by the National Institute of Health.

Even modern drugs that are validated through rigorous double blind studies are not immune from doubts about their effectiveness due to placebo effect. In 2008, PLoS Medicine published a meta-analysis study on the SSRI’s drugs that are routinely used to treat depression

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2582668/ 

Prof. Irving Kirsch  conducted the study and was quoted as saying,  “The results of our meta-analysis showed that people got better on medication, but they also got better on placebo, and the difference between the two was small. In fact, it was below the criterion for clinical significance established by the National Institute for Health and Clinical Excellence (NICE), which sets treatment guidelines for the National Health Service in the UK”.

Intriguingly, acupuncture seems to create both the placebo mediated effect on the brain and the more specific effect, according to a recent study that employed the fMRI technology: “Although controversy regarding appropriate control methodology (e.g. sham acupuncture) continues, data suggest that modulation of certain limbic brain networks may differentiate between specific and placebo components of acupuncture.”

Pain magazine, 2007  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1913212.

So what is the problem using "sham acupuncture" as a control and interpreting results of studies?   In many acupuncture studies, "sham acupuncture" is conducted by using fake needles to create an illusion of acupuncture without penetrating the skin on the same or other acupuncture points that are used in the study. But these devices do stimulate mechanoreceptors, which are the sensory receptors that respond to mechanical pressure.   Way too often in acupuncture research, the so called “control” is not inert, and may have a therapeutic effect (beyond placebo) of its own.

 Another issue is what we call “actual” acupuncture in acupuncture research is often a sub-optimal version of acupuncture. In clinical practice there is more fine-tuning in the selection of the needling sites to account for the clinical diversity and of course patient-healer interactions that add value to the healing session.

Here is the crux of trying to conduct acupuncture research in a randomized, double-blind placebo controlled study using the sham as control.  

What does it mean when “actual” acupuncture works no better than a sham procedure, but both interventions improve patients’ symptoms?

Pick your answer below:

a. Both interventions work as placebos only
b. Both interventions are more than just placebos
c. I can’t answer definitively
d. If the patient feels relief, that's good medicine whatever the cause or reason

Cheers!