[1] Univ Pisa, Dept Translat Res & New Technol Med & Surg, Gastroenterol Unit, Pisa, Italy
[2] Univ Padua, Div Gastroenterol, Dept Surg Oncol & Gastroenterol, Padua, Italy
[3] Univ Padua, Unit Biostat Epidemiol & Publ Hlth, Dept Cardiac Thorac Vasc Sci & Publ Hlth, Padua, Italy
[4] Univ Ferrara, Dept Med Sci, Ferrara, Italy
[5] Nuovo Regina Margherita Hosp, Digest Endoscopy Unit, Rome, Italy
[6] Univ Kansas, Sch Med, Kansas City, MO USA
[7] VA Med Ctr, Kansas City, MO USA