[1] Univ Bern, Dept Social & Prevent Med, Bern, Switzerland
[2] Univ Childrens Hosp, Zurich, Switzerland
[3] Univ Childrens Hosp, Geneva, Switzerland
[4] Univ Childrens Hosp, Lausanne, Switzerland
[5] Univ Childrens Hosp, Basel, Switzerland
[6] Univ Childrens Hosp, Bern, Switzerland
[7] Kantonsspital Luzern, Paediat Dept, Luzern, Switzerland