[1] Univ Bern, Inst Social & Prevent Med, Bern, Switzerland
[2] CHU Vaudois, Dept Femme Mere Enfant, Unite Pneumol & Mucoviscidose Pediat, Lausanne, Switzerland
[3] Univ Lausanne, Lausanne, Switzerland
[4] Kinderpneumol Horgen, Private Practice Paediat Pneumol, Horgen, Switzerland
[5] Univ Childrens Hosp Basel, Dept Paediat Pulmonol, Basel, Switzerland
[6] Univ Bern, Bern Univ Hosp, Inselspital, Div Paediat Resp Med & Allergol,Dept Paediat, Bern, Switzerland
[7] Univ Childrens Hosp Zurich, Dept Resp Med, Zurich, Switzerland
[8] Univ Zurich, Childrens Res Ctr, Zurich, Switzerland
[9] Cantonal Hosp Lucerne, Childrens Hosp, Div Paediat Pulmonol, Luzern, Switzerland