1. Kinderhospital Osnabrueck, Kompetenznetz Patientenschulung e.V, Osnabrueck, Germany
2. Department of Medical Psychology, Hannover Medical School, Hannover, Germany
3. Department of Pediatrics, Children's University Hospital Luebeck, Luebeck, Germany
4. Center of Pediatric Surgery, Hannover Medical School and Bult Children's Hospital, Hannover, Germany
5. Department of Pediatrics, Children's University Hospital Essen, Essen, Germany