If it doesn't work, stop it: Medicine is a science of prediction and intervention

doi:10.1136/bmj.328.7446.1015-a

BMJ 2004;328:1015 (24 April), doi:10.1136/bmj.328.7446.1015-a

Letter

If it doesn't work, stop it

Medicine is a science of prediction and intervention

The first 150 words of the full text of this article appear below.

EDITOR—Assessing effectiveness and benefit in epidemiologicalstudies entails several degrees of imprecision and uncertaintyat the individual level while its estimator is defined for apopulation. A single disease entity may have varied manifestationsin different patients and divergent outcomes.¹

As Anderson and Groves emphasise,² Archie Cochrane posed threekey questions to ask about a healthcare intervention: "Can itwork?" "Does it work in practice?" and "Is it worth it?" Weusually use rules to decide between "yes," "not sure," and "no."By doing this we assume Aristotelian logic and the classic currentdefinition that "health and disease are opposites and that theyare dual and contradictory attributes."¹

Why do doctors use treatments that do not work?³ People usuallydo not require precise numerical information, and yet they arecapable of making decisions. They accept noisy and impreciseinput⁴; so do doctors.

Having a huge number of . . . [Full text of this article]

Ludovic Reveiz, coordinator of general practice

Colsánitas, Cons Clínica Reina Sofía, Bogota, Colombia lureveiz@colsanitas.com