 Measurements at baseline will include: demographics, medical history, medication, co-morbidities, exercise capacity, respiratory parameters, generic and disease-specific health-related quality of life HRQoL, severity of dyspnea, sensory and affective dimensions of dyspnea, impact of dyspnea, cognition, level of daytime sleepiness, and functional capacity. A member of the research team will visit patients after 1 and 2 weeks in their home environment to assess adverse effects, compliance, exacerbations, disease-specific HRQoL, mobility, severity of dyspnea, and some respiratory parameters. A member of the research team will call the patient after 2 days and 3 weeks to assess adverse effects, compliance, exacerbations, and severity of dyspnea. After 4 weeks the following measurements will be performed: respiratory parameters, exercise capacity, general and disease-specific HRQoL, sensory and affective dimensions of dyspnea, impact of dyspnea, functional capacity, and adverse effects. Overnight oximetry will be performed in the home environment at baseline and after four weeks. A diary for costs and healthcare use will be filled in during four weeks. 