[1] Cleveland Clin Fdn, Dept Gastroenterol & Hepatol, Cleveland, OH 44195 USA
[2] Cleveland Clin Fdn, Dept Quantitat Hlth Sci, Cleveland, OH 44195 USA
[3] Geisinger Hlth Syst, Ctr Hlth Res, Danville, PA USA
[4] ChiRhoClin Inc, Burtonsville, MD USA
[5] Brigham & Womens Hosp, Div Gastroenterol Hepatol & Endoscopy, Boston, MA 02115 USA