1. Department of Pediatric Surgery - Pediatric Surgical Center of Amsterdam; Emma Children's Hospital; Academic Medical Center and VU University Medical Center; Amsterdam Netherlands
2. Department of Pediatric Surgery; Wilhelmina Children's Hospital; Utrecht Netherlands
3. Department of Pediatric Surgery; Prinses Maxima Center; Utrecht Netherlands
4. Department of Pediatric Surgery; Uniklinic; Köln Germany
5. Department of Pediatric Surgery; Erasmus MC Sophia Children's Hospital; Rotterdam Netherlands
6. Department of Pediatric Surgery; Amalia Children's Hospital; Radboudumc; Nijmegen Netherlands
7. Department of Pediatric Surgery; Beatrix Children's Hospital; University Medical Center Groningen; Groningen Netherlands
8. Department of Pediatrics; Emma Children's Hospital; Academic Medical Center and VU University Medical Center; Amsterdam Netherlands
9. Department of Pediatric Surgery; Maastricht University Medical Center; Maastricht Netherlands
10. Center of Research on Psychology in Somatic Diseases (CoRPS); Tilburg University; Tilburg Netherlands