[1] Deutsch Rheuma Forsch Zentrum, Leibniz Inst, Programme Area Epidemiol & Hlth Serv Res, Charitepl 1, D-10117 Berlin, Germany
[2] Charite Univ Med Berlin, Dept Pediat Resp Med Immunol & Crit Care Med, Berlin, Germany
[3] Free Univ Berlin, Berlin, Germany
[4] Humboldt Univ, Berlin, Germany
[5] BARMER Inst Hlth Syst Res, Dept Med & Hlth Serv Res, Wuppertal, Germany
[6] Charite Univ Med Berlin, Inst Social Med Epidemiol & Hlth Econ, Berlin, Germany