The Dilemma of Prevention Trials

Abstract

The cognitive goal of every science is to establish causal links between phenomena. Medicine aims first and foremost at discovering the origins of diseases. Certainly, there is a general approach manner, but the development of this science in the last forty years has pertinently shown that the optimal method depends on the disease’s own nature. For instance, chronic diseases which dramatically irrupted in human pathology in the postwar period have imposed the surge and progression of a new epidemiology which completes the clinic and the experimental laboratory as places for the study of an illness. Its object is the community, not the individual or the laboratory animal. The field where it picks up the phenomena and their interrelations is much wider and therefore much wider are the possibilities of detecting two fundamental links beween phenomena: those of simultaneity and of successiveness. The cross section epidemiology looks for simultaneity relations, the prospective one for succession links. The concept of “risk factor” implies a succession link. Epidemiology operates with observations that is with postures in which the research worker is passive. As a matter of fact beyond every phenomenon stands an “intervention”, because nothing can occur without an intervention. This truth lies on the bedrock of the central metaphor of epidemiology: “nature experiments”.