1. Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet Copenhagen University Hospital Copenhagen Denmark
2. Department of Paediatrics Central Hospital Skövde Sweden
3. Institute of Clinical Science, The Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
4. Department of Pediatrics, CF Center Queen Silvia Children's Hospital Gothenburg Sweden
5. Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus Aarhus University Hospital Aarhus Denmark
6. Department of Respiratory Medicine The Children's Hospital at Westmead Sydney New South Wales Australia
7. Department of Clinical Medicine University of Copenhagen Copenhagen Denmark