[1] University Medical Center Hamburg-Eppendorf,Department of Primary Medical Care
[2] Institute of General Practice,Department of Psychiatry and Psychotherapy
[3] University of Jena,Department of Psychiatry and Psychotherapy
[4] Institute of General Practice,Department of Medical Biometry and Epidemiology
[5] University of Frankfurt am Main,Department of Health Economics and Health Services Research
[6] Institute for Social Medicine,undefined
[7] Occupational Health and Public Health,undefined
[8] University of Leipzig,undefined
[9] Central Institute of Mental Health,undefined
[10] University of Heidelberg,undefined
[11] University of Bonn,undefined
[12] Institute of General Practice,undefined
[13] University of Düsseldorf,undefined
[14] Technical University of Munich,undefined
[15] University Medical Center Hamburg-Eppendorf,undefined
[16] Institute for General Practice,undefined
[17] Hannover Medical School,undefined
[18] University Medical Center Hamburg-Eppendorf,undefined