[Clinical epidemiology--the basis for evidence-based medicine].

Contemporary medicine brings requirement of the best available research evidence for the physician's decision on the diagnosis, therapy, prognosis and prevention. Such evidence is provided by clinical epidemiology, which represents the application of principles of the epidemiological methodology into the problems of clinical medicine. The knowledge of basic principles of clinical epidemiology is essential for the use of information of published results of medical research and for their proper and critical interpretation.