1. Department of Surgery, Leiden University Medical Center, Leiden, Netherlands
2. Dutch Institute for Clinical Auditing, Leiden, Netherlands
3. Department of Surgery, Hagaziekenhuis, Den Haag, Netherlands
4. Department of Cardiothoracic Surgery, Radboud University Medical Center, Nijmegen, Netherlands
5. Department of Cardiothoracic Surgery, LUMC, Leiden, Netherlands
6. Department of Surgery, Northwest Clinics, Alkmaar, Netherlands
7. Department of Surgical Oncology, Antoni van Leeuwenhoek Hospital/Netherlands Cancer Institute, Amsterdam, Netherlands