Department of Medical Informatics, Biometry and Epidemiology (IBE), Marchioninistr. 15, 81377 Munich, Germany. boulesteix@ibe.med.uni-muenchen.de|Department of Medical Informatics, Biometry and Epidemiology (IBE), Marchioninistr. 15, 81377 Munich, Germany. boulesteix@ibe.med.uni-muenchen.de