1. Department of Neonatology, Children’s Hospital University of Cologne, Cologne, Germany
2. Department of Neonatology and Pediatric Intensive Care, University Witten-Herdecke, Vest Children's Hospital, North Rhine-Westphalia, Germany
3. Department of Neonatology, Children’s Hospital, University of Lübeck, Lübeck, Germany
4. Department of Neonatology, Children’s Hospital Aschaffenburg, Aschaffenburg, Germany
5. Department of Neonatology, Children’s Hospital Leverkusen, Leverkusen, Germany
6. Department of Neonatology, Asklepios Klinik Barmbek, Hamburg, Germany
7. Department of Neonatology, Children’s Hospital, Ruhr-University Bochum, Bochum, Germany
8. Department of General Pediatrics, University Hospital Düsseldorf, Düsseldorf, Germany
9. Department of Neonatology, Children’s Hospital Siegen, Siegen, Germany
10. Department of Neonatology, University of Bonn, Bonn, Germany
11. Department of Neonatology, Olgahospital Stuttgart, Stuttgart, Germany
12. Department of Neonatology and Pediatric Intensive Care Medicine, Children’s Hospital, Cologne, Germany
13. Department of Neonatology, Charité University Medical Center, Berlin, Germany
14. Institute of Medical Statistics, Informatics, and Epidemiology, University of Cologne, Cologne, Germany
15. Center for Clinical Studies, Cologne, Germany