[The evaluation process of public health action: the challenge of epidemiology]

This paper aims to focus the need of a correct use of epidemiology in the evaluation process of public health actions. It has been described the challenge of epidemiology, at first used mainly for aetiological studies but now much more involved in health services research. Then, considering the fact that in public health every act has to be judged on the basis of its suitability and efficacy, but also of the few financial resources available, the authors stated the importance of the identification of the actual role of the epidemiologists in the evaluation processes and, meanwhile, of their specific training programs. It is eventually underlined that public health, though becoming more and more complex, needs measurable and concrete evaluation indexes and criteria which could lead to a correct selection of the targets and of the actions needed.