[To screen or systematically treat a population at risk? A method based on the analysis of costs applicable at the level of district health].

With severely limited resources, it is necessary for the health services to select the most efficient strategy for managing health problems in a population at risk. A simple method for cost analysis, which can be used at the district health care level, is proposed so that one can choose between selective treatment on the basis of case identification, or indiscriminate treatment of the entire population at risk. The treatment of anaemia at the antenatal clinic in health centres in southwestern Chad was studied and is presented as an example. The conditions for use and the limitations of the method are discussed.