[1] Univ Calgary, Dept Med, Div Gastroenterol & Hepatol, CWPH 6D19,3280 Hosp Dr NW, Calgary, AB T2N 4Z6, Canada
[2] Univ Calgary, Dept Community Hlth Sci, Calgary, AB, Canada
[3] Alberta Hlth Serv, Knowledge Resource Serv, Calgary, AB, Canada
[4] Univ Calgary, Cumming Sch Med, Dept Oncol, Calgary, AB, Canada
[5] Alberta Hlth Serv, Dept Canc Epidemiol & Prevent Res Canc Control Alb, Calgary, AB, Canada
[6] Indiana Sch Med, Div Gastroenterol, Indianapolis, IN USA
[7] Texas Tech Univ, Dept Internal Med, Paul L Foster Sch Med, El Paso, TX USA
[8] Univ Florida, Dept Gastroenterol, Gainesville, FL USA
[9] Univ Calgary, Dept Surg, Calgary, AB, Canada