Archive for March 10th, 2010

Plausibility in Science-Based Medicine

A question that arises often when discussing the optimal role of science in medicine is the precise role of plausibility, or prior probability. This is, in fact, the central concept that separates (for practical if not philosophical reasons) science-based medicine (SBM) from evidence-based medicine (EBM).

The concept featured prominently in the debate between myself and Dr. Katz at the recent Yale symposium that Kimball Atwood recently discussed. Dr. Katz’s treatment of the topic was fairly typical of CAM proponents, and consisted of a number of straw man derived from a false dichotomy, which I will describe in detail below.

I also recently received (I think by coincidence) the following question from an interested SBM reader:

What would Science Based Medicine do if H. pylori was not known, but a study showed that antibiotics given to patients with stomach ulcers eliminated symptoms? I assume that SBM wouldn’t dismiss it outright saying that it couldn’t possibly be helping because antibiotics don’t reduce stomach acid. I assume a SBM approach would do further studies trying to discover why antibiotics work. But, in the meantime, would a SBM practitioner refuse to give antibiotics to patients because he doesn’t have a scientific explanation as to why it works?

This is the exact type of scenario raised by David Katz during our discussion. He claimed that strict adherence to the principles of SBM would deprive patients of effective treatments, simply because we did not understand how they work. This is a pernicious straw man that significantly misconstrues the nature of plausibility and its relationship to the practice of medicine.


Posted in: Science and Medicine

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