1. Department of Medicine, Diakonie Hospital Jung Stilling, Siegen, Germany
2. Phillips-Universität Marburg, Marburg, Germany
3. FOM University of Applied Sciences, Siegen, Germany
4. Department of Internal Medicine I, Johannes-Gutenberg Universität Mainz, Mainz, Germany
5. Department of Heath Services Research, University of Maastricht, Maastricht, Netherlands
6. Institute of General Practice, University of Marburg, Marburg, Germany