1. Departments of Vascular Surgery, Leiden University Medical Centre, Leiden, The Netherlands
2. Departments of Medicine, Leiden University Medical Centre, Leiden, The Netherlands
3. Department of Surgery Onze Lieve Vrouwe Gasthuis, Dutch Cancer Institute – Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
4. Department of Medical Statistics and Bioinformatics, Leiden University, Leiden, The Netherlands
5. Institute of Mathematics, Leiden University, Leiden, The Netherlands
6. Scientific Bureau, Dutch Institute for Clinical Auditing, Leiden, The Netherlands
7. Department of Surgery, Dutch Cancer Institute – Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands