1. Division of Gastroenterology and Hepatology; Department of Internal Medicine III; Medical University of Vienna; Vienna Austria
2. Division of Transplantation; Department of Surgery; Medical University of Vienna; Vienna Austria
3. Department of Intensive Care Medicine; University Medical Centre Hamburg Eppendorf; Hamburg Germany
4. Section for Medical Statistics; Center for Medical Statistics, Informatics, and Intelligent Systems; Medical University of Vienna; Vienna Austria