1. Austrian health insurance fund, Health Center (ÖGK) – Styria, Graz, Austria
2. Medical University of Graz, Institute of General Practice and Evidence-Based Health Services Research, Graz, Austria
3. Medical University of Graz, Institute for Medical Informatics, Statistics and Documentation, Graz, Austria
4. Goethe University Frankfurt, Institute of General Practice, Frankfurt am Main, Hessen, Germany