[1] Univ Western Australia, Sir Charles Gairdner Hosp, Dept Gastroenterol & Hepatol, Crawley, Australia
[2] Univ Western Australia, Sch Populat Hlth, Crawley, Australia
[3] McGill Univ, Ctr Hlth, Div Gen Surg, Montreal, PQ H3G 1A4, Canada
[4] McGill Univ, Ctr Hlth, Div Gastroenterol, Montreal, PQ H3G 1A4, Canada
[5] McGill Univ, Ctr Hlth, Dept Epidemiol Biostat & Occupat Hlth, Montreal, PQ H3G 1A4, Canada
[6] Gustave Roussy Inst Oncol, Endoscopy Unit, Villejuif, Greater Paris, France
[7] Univ Montreal, Div Gastroenterol, Montreal, PQ, Canada