1. Institute of Health Policy & Management; Erasmus University Rotterdam; Rotterdam The Netherlands
2. Department of Neonatology and Paediatric Intensive Care; Children's Hospital; University Hospital of Cologne; Cologne Germany
3. Department of Supply Chain Management & Management Science; Faculty of Management; Economics and Social Science; University of Cologne; Cologne Germany
4. Department of Business Administration and Health Care Management; Faculty of Management; Economics and Social Science; University of Cologne; Cologne Germany