1. Department of Pediatrics and Adolescents Stavanger University Hospital Stavanger Norway
2. Department of Clinical Science University of Bergen Bergen Norway
3. Department of Public Health and Primary Care KU Leuven, University of Leuven Leuven Belgium
4. Department of Pediatrics Landspitali – The National University Hospital Reykjavik Iceland
5. Department of Pediatrics, Faculty of Medicine University of Iceland Reykjavik Iceland
6. Department of Health and Inequality Norwegian Institute of Public Health Oslo Norway
7. Department of Global Public Health and Primary Care University of Bergen Bergen Norway
8. Centre for Fertility and Health Norwegian Institute of Public Health Oslo Norway
9. City Council Department for the Elderly Health and Care, Bergen Municipality Bergen Norway
10. Department of Health Registry Research and Development Norwegian Institute of Public Health Bergen Norway
11. Children and Youth Clinic Haukeland University Hospital Bergen Norway