[1] Univ Copenhagen, Inst Clin Med, Copenhagen, Denmark
[2] Bispebjerg Hosp, Dept Resp Med, Resp Res Unit, Copenhagen, Denmark
[3] Hvidovre Univ Hosp, Dept Resp Med, Hvidovre, Denmark
[4] Aarhus Univ Hosp, Dept Resp Med, Aarhus C, Denmark
[5] LHL Klin Bergen, Nesttun, Norway
[6] Univ Bergen, Dept Clin Sci, Bergen, Norway
[7] Haukeland Hosp, Dept Thorac Med, Bergen, Norway
[8] Uppsala Univ, Dept Med Sci Resp Allergy & Sleep Res, Uppsala, Sweden
[9] Umea Univ, Dept Publ Hlth & Clin Med, Div Med, Umea, Sweden
[10] Skane Univ Hosp, Dept Resp Med & Allergol, Lund, Sweden
[11] Karolinska Univ Hosp, Div Resp Med & Allergy, Stockholm, Sweden
[12] Univ Gothenburg, Inst Med, Krefting Res Ctr, Gothenburg, Sweden
[13] Univ Iceland, Landspitali Univ Hosp Reykjavik Iceland, Dept Allergy Resp Med & Sleep, Reykjavik, Iceland
[14] Univ Iceland, Fac Med, Reykjavik, Iceland
[15] Univ Tartu, Dept Pulm Med, Tartu, Estonia
[16] Tartu Univ Hosp, Dept Pulmponary Med, Tartu, Estonia
[17] Univ Tampere, Fac Med & Life Sci, Tampere, Finland
[18] Tampere Univ Hosp, Allergy Ctr, Tampere, Finland
[19] Univ Helsinki, Dept Allergy Resp Dis & Allergol, Helsinki, Finland
[20] Helsinki Univ Hosp, Helsinki, Finland
[21] Seinajoki Cent Hosp, Dept Resp Med, Seinajoki, Finland