1. Department of Paediatrics, Cystic Fibrosis Centre; Jena University Hospital; Jena Germany
2. Surgical and Perioperative Sciences; Umeå University Hospital; Umeå Sweden
3. Department of Paediatrics; Giessen University Hospital; Giessen Germany
4. CF Center, Chemnitz Hospital; Chemnitz Germany
5. Department of Otorhinolaryngology; University Hospital; Jena Germany