[1] Helsinki Univ Cent Hosp, HUS Med Diagnost Ctr, Dept Clin Physiol, PL 281, Helsinki 00029, Finland
[2] Univ Helsinki, PL 281, Helsinki 00029, Finland
[3] Finnish Inst Occupat Hlth, Helsinki, Finland
[4] Helsinki Univ Hosp, Heart & Lung Ctr, Dept Pulm Med, Helsinki, Finland
[5] Univ Helsinki, Helsinki, Finland
[6] Norwegian Univ Sci & Technol, HUNT Res Ctr, Dept Publ Hlth & Nursing, NTNU, Levanger, Norway
[7] Nord Trondelag Hosp Trust, Levanger Hosp, Levanger, Norway
[8] Univ Gothenburg, Inst Med, Krefting Res Ctr, Dept Internal Med & Clin Nutr, Gothenburg, Sweden
[9] Seinajoki Cent Hosp, Dept Resp Med, Seinajoki, Finland
[10] Tampere Univ, Fac Med & Hlth Technol, Resp Res Grp, Tampere, Finland
[11] Umea Univ, Dept Publ Hlth & Clin Med, OLIN Unit, Sect Sustainable Hlth, Umea, Sweden