1. School of Public Health, Harvard University, Boston, Massachusetts, USA
2. Departments of Surgery, McMaster University, Hamilton, Ontario, Canada
3. Departments of Surgery, Western University, London, Ontario, Canada
4. Neil and Elise Wallace STRATUS Center for Medical Simulation and Center for Surgery and Public Health, Brigham and Women's Hospital, Boston, Massachusetts, USA
5. Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA