1. Department of Paediatric Pulmonology and Allergology; Erasmus MC-Sophia Children's Hospital; Rotterdam The Netherlands
2. Cystic Fibrosis Centre; Azienda Ospedaliera di Verona; Verona Italy
3. Activaero GmbH; Gemünden Germany
4. Department of Pulmonology; Erasmus MC; Rotterdam The Netherlands
5. Department of Biostatistics; Erasmus MC; Rotterdam The Netherlands