“Evidence Based Medicine”: WOK Language and AOK Natural Sciences

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150720-doctor(Originally posted on Activating TOK) When we depend on language to mediate scientific knowledge, the field is ripe for misunderstanding and abuse.  And when life and death are involved, as they often are in medical science, getting it right is important. Hence the attempts of prominent figures who straddle both fields — medical science and communication (e.g. David Gorski, Stephen Novella, John Byrne) — to change terminology when current terminology has created problems. In fact, these medical writers/doctors have created a whole society and web site on the issue: Science Based Medicine: exploring issues and controversies in science and medicine.

The need for one particular new term, though, may seem surprising. “Evidence Based Medicine” is a term that should hardly need changing.  Right?  After all, evidence is exactly that–evidence. And evidence has always (in “modern medicine”) been and should always be the basis of medical science. Right?

Well, apparently, not.  Surprising as it may seem, the term “evidence based medicine” (though not the concept) emerged fully only in 1990. (Consider WOK language and the TOK knowledge framework’s “concepts/language”!) It, and its acronym EBM, “emerged as something that needed a manifesto and an acronym because, in practice–and this is a bit awkward–an awful lot of medicine was still based on things like faith, tradition, and vehemence.” (Paul Ingraham.)

So what went wrong between 1990 and more recent times when, it seems, the term has faltered?

Evidence Base – or Pseudo-Evidence Base?

For part of the answer, flick through a magazine or the web. (The following might not be a bad 5 minute exercise for a class, especially if students have laptops or tablets).  A search for sales of remedies for just about any ailment will quickly reveal how often and how glibly the terms “clinical trials”, “research” or “clinical evidence” pop up.  Paul Ingraham, a science writer, points out, “EBM appears to worship clinical trial evidence above all else…”  John Byrne asks,

“Shouldn’t we first ask ourselves, based on established scientific knowledge, does the claim make any sense? Does the phenomenon in question exist? Is it even plausible?These are critical questions that one should ask before worrying about randomized controlled trials.”

As if that weren’t enough, says Paul Ingraham, “This blind spot has directly contributed to the infiltration of quackery into academic medicine and so-called EBM….”  “This EBM idea, even applied too narrowly, would have worked out pretty well if no one had even been dishonest about the evidence.”

As I noted in a blog post last year (“Skepticism: a million dollar challenge”), the veneer of scientific methodology and language has been misappropriated by climate science “skeptics”.  It should be no surprise that much the same can be true of those who are enticed by illegitimate profiteering–or lunatic fringe ideology.

Thus, “pseudo-evidence based medicine”, as the term goes, is really “quackery that strives to create the appearance of being evidence-based.”  It is difficult to find much consolation in the fact that the bad guys at least reinforce in the public’s mind the compelling importance of proper validation of hypotheses through testing–rather than “faith, tradition, or vehemence.”

The most striking abuse of the language of clinical trials, it seems, is in two main forms:

  1. False claims that clinical trials have shown…..etc.
  2. Disingenuous assertions that “more study” is needed.

Tooth Fairy Science

Yet, in both cases, the actual substance of the preposterous claims flies in the face of thoroughly researched and substantiated scientific facts.  Harriet Hall, MD illustrates this principle with her idea of “Tooth Fairy Science“. Tooth Fairy science seeks explanations for things before establishing that those things actually exist. For example:

“You could measure how much money the Tooth Fairy leaves under the pillow, whether she leaves more cash for the first or last tooth, whether the payoff is greater if you leave the tooth in a plastic baggie versus wrapped in Kleenex. You can get all kinds of good data that is reproducible and statistically significant. Yes, you have learned something. But you haven’t learned what you think you’ve learned, because you haven’t bothered to establish whether the Tooth Fairy really exists.”

 Some thoughtful students could well object at this point. What, they might ask, of new scientific principles? Does not the emphasis on pre-established principles prevent new discoveries? No, says Byrne:

This is not to say that we need a plausible, basic science explanation for all claims. We can (and do) rely on evidence only from clinical trials to support the use of many treatments for which we do not have a basic science explanation. Although science tends to fill in the missing mechanisms as we discover new aspects of basic science, we have used many treatments with only clinical evidence. The value of hand washing was discovered as a result of the clinical studies done by Ignaz Semmelweis. There was no basic science of microbiology at the time. The basic neurophysiology of many psychotropic medications was unknown (and still is in some cases). They have been used because clinical trials confirmed that they work. 

So, a known basic science mechanism of action is not really needed to study a claim. However, ** a claim should not contradict established basic science knowledge**.  The above examples did not contradict any scientifically established facts, laws or theories of physics, chemistry or biology.  In fact, the clinical knowledge that came from these examples sparked the search for new basic science knowledge.

TOK teachers and students might well recognize in Harriet Hall’s comments on the tooth fairy some of the drawbacks of the coherence check for truth, when a body of knowledge claims, internally harmonious just as is a mathematical system based on reason, becomes a self-referencing and self-reinforcing bubble. They might equally recognize in Byrne’s comments above a distinction between two checks for truth – the pragmatic test for truth based on practical results and the correspondence check for truth based on evidence. (See truth checks in chapter 3 in the TOK Course Book.)

“Evidence Based Medicine” vs “Science Based Medicine”

The remedy?  The introduction of the term “Science Based Medicine” clearly comes with the intention not to subvert the essential importance of “evidence” from clinical trials, but rather to elevate the equally essential importance of proven science. (Classes familiar with the principle of the Baye’s Factor, Likelihood Ratio, or Bayesian Probability might find it helpful to have those terms applied to this principle.)

If, indeed, Science Based Medicine does replace EBM as the “gold standard”, then several goals will be met:

  1. Claims that blatantly violate proven science will absorb fewer resources in more and yet more costly clinical trials.  Do we really need to prove yet again pure water is not a cure for cancer–or anything else very much (except thirst?)
  2. Fake medicine-men would be less able to parasitize the credulous public while claiming the need for “further trails.”

It seems only too appropriate that Paul Ingraham should invoke that essential litmus paper test first stated by science writer Carl Sagan: “Extraordinary claims require extraordinary evidence”.


The arguments for pushing the term Science Based Medicine provide an excellent example of the constant need to scrutinize our terminology for what it means and how it is used, in practice, to clarify ideas or sometimes (even deliberately) to confuse them. In IB Theory of Knowledge we confront ambiguous and slippery language not only in our specific treatment of language as a way of knowing but also in our examination of concepts and language in areas of knowledge.

In TOK we also give appreciation to scientists trying to improve their area of knowledge in terms of the ways of knowing that underlie it within its overall methodology.  Clearly, we will want give our applause to John Byrne as he calls for careful treatment of evidence:

“The call for SBM is not a call to end EBM. It is a call to advance the evidence-driven paradigm; to fill in the crack that lets in the wedge of pseudoscience. They should be one and the same.

“If we recognize this, we just might get it right.” 


Eileen Dombrowski, Lena Rotenberg, and Mimi Bick. Theory of Knowledge Course Book (in cooperation with the IB). Oxford University Press, 2013. https://global.oup.com/education/product/9780199129737/?region=international

website Science Based Medicine: exploring issues and controversies in science and medicine. https://www.sciencebasedmedicine.org/about-science-based-medicine/

John Byrne, “EBM vs SBM”, Skeptical Medicine https://sites.google.com/site/skepticalmedicine//ebm-vs-sbm

Paul Ingraham “Why ‘Science’-Based Instead of ‘Evidence’-Based? The rationale for making medicine more science-based” updated Aug 26th, 2014 https://www.painscience.com/articles/ebm-vs-sbm.php

Robert Todd Carroll, “Tooth fairy science and Fairy Tale science”, The Skeptic’s Dictionary. http://www.skepdic.com/toothfairyscience.html

satire: David Isaacs and Dominic Fitzgerald. “Seven alternatives to evidence based medicine” Cite this as: BMJ 1999;319:1618. http://www.bmj.com/content/319/7225/1618

Image: Doctor by geralt, Creative Commons via Pixabay