[1] Charite, Dept Pediat Pneumol & Immunol, D-13353 Berlin, Germany
[2] Charite, Social Pediat Ctr, D-13353 Berlin, Germany
[3] Childrens Hosp, Cologne, Germany
[4] Werner Otto Inst, Hamburg, Germany
[5] Childrens Hosp Altona, Hamburg, Germany
[6] Ctr Pediat Neurol Dis, Mainz, Germany
[7] Childrens Hosp Auf der Bult, Dept Pediat Surg, Hannover, Germany
[8] Charite, Inst Social Med Epidemiol & Hlth Econ, D-13353 Berlin, Germany
[9] Robert Koch Inst, Dept Epidemiol & Hlth Reporting, D-1000 Berlin, Germany