1. Child and Adolescent Health; Aarhus University Hospital; Aarhus Denmark
2. Department of Paediatrics and Adolescent Medicine; University Hospital Rigshospitalet; Copenhagen Denmark
3. Department of Paediatrics; Institution for Clinical Sciences; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
4. Department of Bio- and Health Informatics; Technical University of Denmark; Kongens Lyngby Denmark
5. Department of Women's and Children's health; Uppsala University; Uppsala Sweden
6. Department of Women's and Children's health; Childhood Cancer Research Unit; Karolinska University Hospital and Karolinska Institute; Stockholm Sweden
7. Children's Hospital; Landspitali University Hospital; Reykjavik Iceland
8. Department of Paediatric and Adolescent Medicine; Turku University Hospital and Turku University; Turku Finland
9. Department of Paediatrics; St. Olavs Hospital; Trondheim Norway
10. Department of Oncology and Haematology; University Children's Hospital; Tallinn Estonia
11. Clinic of Children's Diseases; Faculty of Medicine; Vilnius University; Vilnius Lithuania