1. Paediatric Department, Stavanger University Hospital , Stavanger , Norway
2. Department of Clinical Science, University of Bergen , Bergen , Norway
3. Department of Neonatal Intensive Care, Clinic of Paediatric and Adolescent Medicine, Oslo University Hospital , Oslo , Norway
4. Paediatric Department, Akershus University Hospital , Lørenskog , Norway
5. Department of Paediatrics, St.Olavs Hospital, Trondheim University Hospital , Trondheim , Norway
6. Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology , Trondheim , Norway
7. Department of Paediatrics and Adolescent Medicine, Haukeland University Hospital , Bergen , Norway
8. Department of Global Public Health and Primary Care, University of Bergen , Bergen , Norway
9. Department of Paediatrics, Møre and Romsdal Hospital Trust , Ålesund , Norway
10. Clinical Research Unit, Norwegian University of Science and Technology , Trondheim , Norway
11. Department of Paediatric and Adolescent Medicine, Ostfold County Hospital , Gralum , Norway
12. Medical Faculty, Institute for Clinical Medicine, University of Oslo , Oslo , Norway
13. Department of Paediatrics and Adolescent Medicine, University Hospital of North Norway , Tromsø , Norway
14. Paediatric Research Group, Faculty of Health Sciences, UiT-The Arctic University of Norway , Tromsø , Norway