1. Department of Occupational and Environmental Medicine, Vejle Hospital, Vejle, Denmark
2. Department of Occupational and Environmental Medicine, Odense University Hospital, Odense, Denmark
3. Department of Occupational and Environmental Medicine, Hospital of Southern Jutland, Haderslev, Denmark
4. Department of Occupational Medicine, Hospital of Southwest Jutland, Esbjerg, Denmark
5. Department of Occupational Medicine, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark
6. Institute of Public Health Medicine, Aarhus University, Aarhus, Denmark
7. Department of Pulmonary Medicine, Odense University Hospital, Odense, Denmark