LETTERS TO THE EDITOR: Letters & Announcements
To the Editor:
Proponents of evidence-based medicine (EBM) insist that reviewers search thoroughly for all evidence relevant to a clinical question. Yet when reviewing the subject of EBM itself, these same proponents seem curiously blind to criticism. In their “review,” Pronovost et al. (1) do not review the considerable academic debate that there has been over EBM; they merely describe what EBM is, and how anesthetists should go about it. At the very least, they should have cited Horan’s editorial (2), and answered the points he made.
No one argues against using evidence when choosing treatments; the disagreements arise when we consider what evidence is appropriate. Pronovost et al. rightly state that the philosophical foundation for EBM is clinical epidemiology—but this is the core of the problem. As Charlton pointed out (3,4), and as I have cited before (5), epidemiology does not provide the information necessary to treat individuals. There are also difficulties with randomized controlled trials (6), to which EBM—even if it does include other forms of evidence—tends to give precedence.
There is no space in a letter to present arguments in detail, but there is plenty of material for interested readers, for example (7–11). It is a shame that Pronovost et al. did not cite any at all; Greenhalgh (12) —also an enthusiast for evidence-based medicine—managed to do so in a recent essay.
An irony of evidence-based medicine is that it claims to be nonauthoritarian; unlike the old authority of expert-based medicine, anyone can learn the techniques, and therefore anyone can apply them. But the reality is that individual practitioners do not have the time to apply EBM to every clinical question, and therefore have to rely on EBM as the new authority. It is an added irony that Pronovost et al. cite, as a source for “well described methods for their conduct,” the Cochrane systematic review of the use of albumin. This review was severely criticized at the time (13), and later by Horsey (14), who reexamined the included trials, and was also critical that the reviewing group did not include an intensive care clinician.
Pronovost et al. cite a paper (15) that is a light-hearted summary of alternatives to EBM such as “eminence-based medicine,” a paper that has a footnote in which the authors explicitly state that they each contributed half the jokes. This is a variation on what Shahar (16) wrote was the most common method of responding to criticism of EBM: turning a deaf ear.
Neville W. Goodman, DPhil, FRCA
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15. Isaacs D, Fitzgerald D. Seven alternatives to evidence-based medicine. BMJ 1999; 281: 714–9.
16. Shahar E. Evidence-based medicine: a new paradigm or the emperor’s new clothes? J Eval Clin Pract 1999; 4: 277–82.