1. Department of Surgery, Leiden University Medical Center, Leiden, Netherlands
2. Scientific Bureau, Dutch Institute for Clinical Auditing, Leiden, Netherlands
3. Department of Surgical Oncology, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands
4. Department of Cardiothoracic Surgery, Radboud University Medical Center, Nijmegen, Netherlands
5. Department of Surgery, HAGA Hospital, Den Haag, Netherlands
6. Faculty of Medicine, Leiden University, Leiden, Netherlands
7. Department of Surgery, Amsterdam UMC, VU University Medical Center, Amsterdam, Netherlands
8. Department of Cardiothoracic Surgery, Amsterdam UMC, VU University Medical Center, Amsterdam, Netherlands
9. Department of Surgery, Northwest Clinics, Alkmaar, Netherlands