1. Department of Thoracic Medicine; Haukeland University Hospital; Bergen Norway
2. Norwegian National Centre of Excellence in Home Mechanical Ventilation; Haukeland University Hospital; Bergen Norway
3. Department of Global Public Health and Primary Care; Faculty of Medicine and Dentistry; University of Bergen; Bergen Norway
4. Department of Clinical Science; Faculty of Medicine and Dentistry; University of Bergen; Bergen Norway
5. Centre for Clinical Research; Haukeland University Hospital; Bergen Norway