1. Department of Pediatrics; Herlev Hospital; Herlev Copenhagen Denmark
2. Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
3. Department of Clinical Sciences; Lund University/CRC, Skåne University Hospital SUS; Malmö Sweden
4. Department of Pediatric Medicine; Oslo University Hospital; Oslo Norway
5. Children's Medical Center; Landspitali University Hospital; Reykjavik Iceland
6. Department of Pediatrics; University of Iceland; Reykjavik Iceland
7. Department of Pediatrics, Institute of Clinical Sciences; The Sahlgrenska Academy at Gothenburg University; Gothenburg Sweden