1. Department of Pediatric Surgery, University of Leipzig, 04103 Leipzig, Germany
2. Section of Thoracic Surgery, Department of Visceral-, Transplant-, Thoracic and Vascular Surgery, University of Leipzig, 04103 Leipzig, Germany
3. Center for Health Economics Research Hannover (CHERH), 30159 Hannover, Germany
4. AOK PLUS-Die Gesundheitskasse fuer Sachsen und Thueringen, 01067 Dresden, Germany
5. AOK-Die Gesundheitskasse fuer Niedersachsen, 30519 Hannover, Germany