Missed opportunity: how many of the placebos "prescribed" were herbal or non-botanical dietary supplements?

ResearchBlogging.org"Prescribing 'placebo treatments': results of national survey of US internists and rheumatologists," is the title of a newly-published article in the 23 October issue of BMJ (British Medical Journal). The full text article and PDF are available for free at the time of this posting.

In this study of 679 US physicians, Tilburt et al. reveal that 46-58% of those responding report regularly using some sort of placebo in their practice. The reason for the range is that questions were asked in a manner that did not use the word, "placebo," but instead took into account:

"Placebo treatment" is an unclear and complicated concept that lacks a standard definition. Placebo treatments include "inert" agents that have little or no pharmacological activity, such as sugar pills and saline injections given to promote positive expectation, and physiologically active agents, such as vitamins or antibiotics, that the physician prescribes solely or primarily to promote positive psychological effects

Dr Jake Young at Pure Pedantry does a superb job covering the article and I encourage you to read his take. Janet Stemwedel, house ethicist, takes me by surprise a bit by suggesting a scenario whereby use of a placebo might be considered ethical.

Since these bloggers wrote about the ethical issues, I am more interested in what kinds of things were suggested by doctors as placebo treatments in that the study was funded in part by the NIH National Center for Complementary and Alternative Medicine (NCCAM). moreover, one of the authors is a relatively well-known, Harvard-affiliated doctor of oriental medicine.

The authors did indeed separate placebos into "inactive" and "active," the latter to denote over-the-counter analgesics or vitamins that possess physiological activity but whose use is not supported clinically for treatment, for example, of non-diabetic patients with fibromyalgia (one scenario in the BMJ paper). So-called "active" placebos were most commonly reported as follows:

[O]ver the counter analgesics (41%), vitamins (38%), antibiotics (13%), and sedatives (13%). Only 2% recommended "sugar pills" and 3% saline.

What disappointed me was that this group did not delve deeper into "vitamins," especially since the NCCAM mission is to investigate the prevalence of dietary supplement use. While not clear from the paper, my interpretation is that herbal supplements (like Echinacea) or non-botanical supplements (like glucosamine) could have also been considered under the broad subheading of "vitamins," particularly since these choices were absent from the survey.

Why do I care to make this distinction or want to know the data?

I fear that as alternative medicine has infiltrated well-regarded academic medical centers and the private practices of board-certified physicians, the suggested use of dietary supplements by some docs as something that "can't hurt" might also be classified as a placebo in the context of this study. I suspect that most physicians are aware that the majority of well-controlled, randomized clinical trials have failed to show any clinical efficacy for but a handful of dietary supplements. The fact that some academic integrative medicine centers actually sell supplements on-site says to me that placebos are being actively promoted in conventional medical practice.

The NCCAM website already has a new release about about this study. I'm a bit concerned as to how this news will be interpreted. The title of the press release, "Half of Surveyed Physicians Use Placebo Treatments for Patients," may lead some readers to believe that if placebo use is so prevalent, then it is ethically reasonable to use ineffective dietary supplements. Or, I could just be paranoid and NCCAM simply wants to advertise that a study they supported made it into BMJ.

Anyway, I may contact the authors and find out if they stratified the responses to determine if they have any information on the use of dietary supplements as placebos in this study.

J. C Tilburt, E. J Emanuel, T. J Kaptchuk, F. A Curlin, F. G Miller (2008). Prescribing "placebo treatments": results of national survey of US internists and rheumatologists BMJ, 337 (Oct 23 (2)) DOI: 10.1136/bmj.a1938


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