1. Faculty of Health and Healthcare Sciences, Ostfalia University of Applied Sciences, 38440 Wolfsburg, Germany;
2. Faculty of Management, Economics and Social Sciences, Department of Business Administration and Healthcare Management, University of Cologne, 50923 Cologne, Germany;
3. Medical Faculty and Cologne University Hospital, Department of Pediatrics, University of Cologne, 50937 Cologne, Germany;
4. Cambridge Judge Business School, University of Cambridge, Cambridge CB2 1AG, United Kingdom