The methodology of cardiovascular disease epidemiology.

Chronic disease epidemiology emerged from a methodological necessity, namely to break the deadlock of the medical science faced with a sudden upsurge of these diseases, especially cardiovascular, after the Second World War. The author analyses the shortcomings of clinical investigation in contrast with the epidemiological approach, the qualitative and quantitative prerequisites of the latter, as well as its methodological instruments, pointing out misunderstandings and improper uses of some terms i.e., epidemiology is not one and the same thing as ecology; epidemiology precludes passive detection; the environmental agent is not identical to the risk factor; the risk factor is not diagnostic. It is worth making these distinctions in order to enhance the value of epidemiology as a first step toward prevention.