[Epidemiologic study of symptoms of minimal brain dysfunction. 1. Design and testing of methods--the incidence of symptoms in the study group].

The authors inform on the elaboration of a screening method for recording of symptoms of minimal brain dysfunction and its initial verification in the research problem "Incidence of signs of minimal brain dysfunctions in children in the North Bohemian region". In the first stage a population group of children in the second form of primary school in three districts was examined, a total of 5080 children, and data were assembled from their 9000 parents. The authors describe the elaboration of the method which comprises rating scales which evaluate specific striking features in the behaviour, dysfunction in school skills (the forms were completed by teachers and mothers) and performance tests administered by the children themselves. Results of statistical analyses which confirmed the satisfactory consistency, composition, empirical and postdictive validity of the method are presented. The analyses revealed that the method used detects disorders included under the term of minimal brain dysfunctions and probably also disorders with the incidence of some identical symptoms (disorders of intellect, behavioural disorders in the wider sense of the word). The authors inform on the method of calculation and the ratio of the detected problem child population which was 14.8%. The group comprises 4.8% children which were unable to keep up with the first form of primary school and attend some special school. The method used detected, however, another 10% population with identical values. The authors discuss problems of screening diagnosis of specific developmental learning and behavioural disorders which form part of minimal brain dysfunctions. Problems associated with the evaluation of the assembled findings are discussed.