1. Institute of General Practice/Family Medicine, Philipps University of Marburg, Karl-von-Frisch-Straße 4, 35043 Marburg, Germany
2. Institute of General Practice, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Universitätsstr. 29, 91054 Erlangen, Germany
3. Association of Statutory Health Insurance Physicians, Bavaria, Elsenheimerstraße 39, 80687 München, Germany