[1] Helmholtz Zentrum Munchen, German Res Ctr Environm Hlth, Inst Asthma & Allergy Prevent IAP, Neuherberg, Germany
[2] Natl Inst Hlth & Welf THL, Dept Hlth Secur, Kuopio, Finland
[3] Univ Helsinki, Dept Publ Hlth, Helsinki, Finland
[4] CK CARE, Davos, Switzerland
[5] Univ Zurich, Childrens Hosp, Zurich, Switzerland
[6] Childrens Hosp Schwarzach, Schwarzach, Austria
[7] Univ Besanon, Univ Hosp, Dept Resp Dis, Besanon, France
[8] Ludwig Maximilians Univ Munchen, Dr von Hauner Childrens Hosp, Munich, Germany
[9] German Ctr Lung Res DZL, Munich, Germany