[Epidemiology of noninfectious diseases--principles and methodology]

Contemporary epidemiology as a science extends considerably its object of research interest. Originally it was interested in the prevalence of communicable diseases in the population and investigated all the factors, which affected this distribution. In the last few decades, epidemiology passed from following-up of communicable diseases to the description and the analysis of all diseases, which occur on our planet. Because of interest in the diseases, which endanger civilization as a result of its development, is the epidemiology with this target is called sometimes the epidemiology of non-communicable diseases. Traditional and the historical experience of communicable diseases epidemiology, methods of the classic statistics and the epidemiological working method are its basic principles. Adequate design of epidemiological studies and modern indicators for evaluation of the health status are used. Epidemiology does not investigate the disease and the risk factor separately, but they are analyzed mutually at three levels as a relation, association and causality. Emphasis is laid on minimalization or complete elimination of confounding and bias.