1. Medical University of Graz; Institute of General Practice and Evidence-Based Health Services Research; Auenbruggerplatz 2/9 Graz Austria 8036
2. Medical University of Graz; Institute of General Practice and Evidence-Based Health Services Research / Institute of Medical Informatics, Statistics and Documentation; Auenbruggerplatz 2/9 Graz Austria 8036
3. Medical University of Graz; Institute of General Practice and Evidence-Based Health Services Research / Department of Internal Medicine, Division of Endocrinology and Metabolism; Auenbruggerplatz 2/9 Graz Austria 8036
4. Graz, Austria / Institute of General Practice, Goethe University; Institute of General Practice and Evidence-Based Health Services Research, Medical University of Graz; Frankfurt am Main Germany