1. Department of Pulmonary Diseases and Clinical Allergology, University of Turku, Turku, Division of Medicine, Department of Pulmonary Diseases, Turku University Hospital, Turku
2. Department of Respiratory Medicine, Kuopio University Hospital, Kuopio
3. Finnish Lung Health Association (FILHA), Helsinki, Finland
4. Lung Clinic of Tartu University Hospital, Tartu, Estonia
5. National Institute for Health Development, Tallinn, Estonia
6. Department of Pulmonary Diseases and Clinical Allergology, University of Turku, Turku