The five normative postulates of Evidence Based Medicine

Evidence Based Medicine (EBM) is rooted in five linked ideas [Davidoff, Haynes, Sackett  & Smith, 1995]:

1.     Clinical decisions should be based on the best available scientific evidence.

2.     The clinical problem-rather than habits or protocols-should determine the type of evidence to be sought.

3.     Identifying the best evidence means using epidemiological and biostatistical ways of thinking.

4.      Conclusions derived from identifying and critically appraising evidence are useful only if put into action in managing patients or making health care decisions.

5.     Performance should be constantly evaluated.

The five normative postulates express a program for medical practice which has been widely and enthusiastically accepted by the medical community.

Postulate one is a call for continuous formation on the part of the physician, the acknowledgement of the rapid and continuous development of life sciences and the imperative need for theoretical and practical updates in the fields of those sciences: medical education is an ongoing process. One major problem with this sound proposal is the availability and transparency of scientific information: human health is an industry and information is restricted by market conditions. Besides this social objection to the implementation of the postulate, we meet an epistemological one: the concept of medical evidence is problematic.  The problem is subsumed under the belief in the unquestionable validity of the randomized controlled trials, but the statistical efficacy of a treatment, per se, is not sufficient for its implementation: statistical evidence needs also theoretical integration, i.e., has to be understood in a wider reference frame if we want to have some control over possible perverse effects (using Merton’s trerminology) unforeseen in statistical conceptual frames. In the health sciences, it is now a commonplace that both mechanistic and probabilistic evidence are required to substantiate causal claims [Russo and Williamson, 2007]. The history of medicine presents many cases in which causal claims made solely on the basis of statistics have been rejected until backed by mechanistic or theoretical knowledge [Russo and Williamson, 2007].

Postulate two expands what was said in postulate one, it is basically a call against inertia and mechanic medical action. Its implementation encounters several economic problems.

Postulate three is an epistemological declaration: the medical method should be mainly statistical. As we just said, biostatistics by itself is not enough for medical practice: without a theoretical frame, statistics is nothing but uninterpreted data. On the other hand, the implementation of a health program not fully understood is a plea for what the social sciences call perverse effects.

Postulate four is an ethical demand for the EBM program: the purpose of the medical practice is to cure patients. In this sense, is not a dehumanized practice as its opponents advocate. On the other hand, we could not say that EBM expresses a humanistic approach, for it has not an anthropological perspective upon the medical practice as a social action.

Finally, postulate five extends the ideas expressed in P1 and P2.

References

Davidoff, F., Haynes, B., Sackett, D., and Smith, R. Evidence-based medicine. [1995]. British Medical Journal, 310, 1085–1086.

Russo, Federica, and Williamson, Jon.  Interpreting Causality in the Health Sciences. [2007] International Studies in the Philosophy of Science. Vol. 21, No. 2, July 2007, pp. 157–170.