Department of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-Universitaet, Muenchen, Germany. mansmann@ibe.med.uni-muenchen.de|Department of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-Universitaet, Muenchen, Germany. mansmann@ibe.med.uni-muenchen.de