In order to perform constant epidemiological research it is proposed that continuous household interview survey be carried out in conjunction with the public health service, coordenated by the University. A previous field experiment, carried out in the city of Ribeirão Preto, S. Paulo State, Brazil, between 1972 and 1978, is discussed and some problems and their proposed solutions are presented. The problem of lay reporting of morbidity classification is analysed.
Epidemiologic methods; Sampling studies; Health surveys