1. Department of Pediatrics, Institute of Clinical Science at Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
2. Department of Pediatrics Queen Silvia's Children Hospital Gothenburg Sweden
3. Statistiska Konsultgruppen Gothenburg Sweden
4. Department of Pediatrics, Lund CF Centre Skåne University Hospital Lund Sweden
5. Department of Pediatrics, Uppsala CF Centre Uppsala University Hospital Uppsala Sweden
6. Stockholm CF Centre Karolinska University Hospital Huddinge Stockholm Sweden
7. Department of Clinical Science, Intervention and Technology, Division of Pediatrics Karolinska Institute Stockholm Sweden