1. Institute for Medical Sociology, Health Services Research and Rehabilitation Science University of Cologne; Faculty of Human Sciences and Faculty of Medicine (IMVR); University of Cologne; Cologne Germany
2. Department for Research Methodology; University of Education; Freiburg Germany
3. Scientific Institute of Office-Based Haematologists and Oncologists (WINHO); Cologne Germany
4. Professional Organization of Office-Based Haematologists and Oncologists e.V. (BNHO); Cologne Germany
5. Faculty of Health; School of Medicine; Witten/Herdecke University; Herdecke Germany