[Methods for the evaluation of a health intervention in developing countries: the case in the Arsi region, Ethiopia].

Since 1989 an evaluation study of the impact of a Primary Health Care (PHC) program is being carried out in Arsi region, Ethiopia. The principal aim of the study is to estimate the mortality rates in those villages mainly involved in PHC activities. A sample of 80 villages will be recruited to allow significant differences in mortality of 20 per thousand between less treated and best treated villages. Considering the absence of routine demographic data, a population census and demographic surveillance of the recruited villages have been carried out. All the activities related to the study are considered together with the principal logistic and methodologic problems.