Methods: Prior to discharge a semistructured interview designed to explore the experience of using noninvasive ventilation will be undertaken by a clinical psychologist from the Cystic Fibrosis multidisciplinary team. The interviews will be undertaken purely for the research project, recorded and transcribed verbatim by the lead investigator. Thematic analysis will be undertaken to interpret and explore the individual's experience. Credibility checking of interpretation will be undertaken by the clinical psychologists and within academic supervision sessions.