[1] Charite, Inst Social Med Epidemiol & Hlth Econ, D-10117 Berlin, Germany
[2] Charite, Dept Neurol, Charitepl 1, D-10117 Berlin, Germany
[3] Univ Hosp Eppendorff, HanseMerkur Ctr Tradit Chinese Med, Martinistr 52, D-20246 Hamburg, Germany
[4] Charite, Inst Social Med Epidemiol & Hlth Econ, Luisenstr 57, D-10117 Berlin, Germany