1. Department of Clinical Physiology, HUS Medical Diagnostic Center, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
2. Department of Pulmonary Medicine, Heart and Lung Center, Helsinki University Hospital and Helsinki University, Helsinki, Finland
3. Finnish Institute of Occupational Health, Helsinki, Finland
4. HUNT Research Centre, Department of Public Health and Nursing, NTNU, Norwegian University of Science and Technology, Levanger, Norway
5. Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway
6. Krefting Research Centre, Institute of Medicine, Department of Internal Medicine and Clinical Nutrition, University of Gothenburg, Gothenburg, Sweden
7. Department of Respiratory Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland
8. Tampere University Respiratory Research Group, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
9. Department of Public Health and Clinical Medicine, Section of Sustainable Health, The OLIN unit, Umeå University, Umeå, Sweden
10. Department of Health Sciences, Luleå University of Technology, Luleå, Sweden