University of Würzburg - Department of Internal Medicine II, University of Freiburg - Medical Center, Ulm University, University of Tuebingen, Faculty of Medicine, Institute for Clinical Epidemiology and Applied Biometry, University of Regensburg, University of Oldenburg, University of Hanover, Robert-Bosch-Hospital, Ulm University, Munich Schwabing Hospital, Otto-von-Guericke-Universität Magdeburg, Charite-Oncology Centre, Red Cross Hospital, Munich, University Hospital Grosshadern, Technische Universität München (TUM), Universitätsmedizin Mainz, Klinikum Bremen Mitte, University of Rostock, University of Munster, University of Greifswald - University Hospital Greifswald, Martin Luther University of Halle-Wittenberg, Zentrum Innere Medizin, Dr. Horst-Schmidt-Klinik, University of Würzburg - Department of Internal Medicine II, Charité - Universitätsmedizin Berlin, Ernst von Bergmann Hospital, Bolzano Municipal Hospital, Ulm University, Schleswig-Holstein University - University Hospital Center, Stauferklinikum Schwäbisch Gmünd, University of Tuebingen - University Hospitals Tübingen, University of Würzburg - Department of Internal Medicine II and Independent