1. Unit of General Surgery and Surgical Oncology, Department of Medicine, Surgery and Neurosciences University of Siena Siena Italy
2. Surgical Unit ‘M. Rubino’, Department of Emergency and Organ Transplantation University ‘Aldo Moro of Bari’ Bari Italy
3. Statistics Division, The George Institute for Global Health University of New South Wales Sydney New South Wales Australia
4. II Surgery Unit Regional Hospital Treviso, AULSS2 Treviso Italy
5. Department of Medicine – DIMED University of Padua Padua Italy
6. Department of Colorectal Surgery S. Rita Clinic Vercelli Italy
7. Department of Surgery, Oncology and Gastroenterology – DISCOG University of Padua Padua Italy