[1] Heidelberg Univ Hosp, Dept Gen Practice, Neuenheimer Feld 130-3, D-69120 Heidelberg, Germany
[2] Heidelberg Univ Hosp, Hlth Serv Res, Neuenheimer Feld 130-3, D-69120 Heidelberg, Germany
[3] Leibniz Inst Prevent Res & Epidemiol BIPS GmbH, Achterstr 30, D-28359 Bremen, Germany