[The most prevalent errors in screening studies].

Abstract

The article presents theoretical foundations of screening research in epidemiology. In planing of screening study several features of the disease should be considered such as severity and prevalence of studied disease as well as availability of treatment for it and also availability of appropriate tests which enable screening program at the affordable cost. Evaluation of screening may be based on the number of early diagnoses or on the difference in survival time between people who are screened and those who are not. Any analysis of the effects of screening program may have pitfalls leading to incorrect assessment. The most prevalent errors such as selection bias and measurement error are discussed.