1. The Department of Paediatric and Adolescent Medicine, Akershus University Hospital, P.O. Box 1000, 1478 Lørenskog, Norway
2. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, P.O. Box 1171, 0318 Oslo, Norway
3. The Department of Anaesthesia and Intensive Care Unit, Stavanger University Hospital, P.O. Box 8100, 4068 Stavanger, Norway
4. Department of Paediatrics and Adolescent Medicine, Østfold Hospital Trust Kalnes, P.O. Box 300, 1714 Grålum, Norway
5. Department of Paediatrics and Adolescent Health, University of Botswana, Private Bag, Gaborone 0022, Botswana
6. Department of Neonatal Intensive Care, Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Rikshospitalet, Nydalen, P.O. Box 4950, 0424 Oslo, Norway