[Some considerations concerning the concept of risk in public health (author's transl)]

The use of risk in Public Health consists schematically of two steps: the calculation of risk, and then action intended to reduce it. The calculation, taking into account the largest possible number of risk factors, can produce a risk value adjusted to the individual. Action was, in past, directly oriented by risk factors which caused the risk. But, now, that the approach to risk has become more indirect by taking into consideration predictive factors without a causative role, their use in action to reduce risk requires discussion. Thus it has seemed necessary to examine the situation in several pathological fields; substantial differences in uses of risk values were found according to the field taken into consideration. The point in common remains the attempt of an ideal approach guided by an overall assessement of cost and effectiveness, involving the cost of determining the risk and the advantages and costs of the resulting action.