1. Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway;
2. Department of Pediatrics and
3. Department of Clinical Science, University of Bergen, Bergen, Norway;
4. Faculty of Health and Social Sciences, Western Norway University of Applied Sciences, Bergen, Norway; and
5. Department of Otolaryngology, Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway;
6. Norwegian School of Sports Sciences, Oslo, Norway