1. Department of Surgery, Erasmus MC – University Medical Centre, Rotterdam, The Netherlands
2. Department of Biostatistics, Erasmus MC – University Medical Centre, Rotterdam, The Netherlands
3. Department of Surgery, IJsselland Ziekenhuis, Capelle a/d IJssel, The Netherlands
4. Department of Surgery, Maasstad Ziekenhuis, Rotterdam, The Netherlands
5. Department of Surgery, Ikazia Ziekenhuis, Rotterdam, The Netherlands