[1] Univ Washington, Harborview Med Ctr, Sch Med, Div Gastroenterol, Seattle, WA 98104 USA
[2] Brigham & Womens Hosp, Div Gen Internal Med, Boston, MA 02115 USA
[3] Harvard Univ, Sch Med, Dept Hlth Care Policy, Boston, MA 02115 USA
[4] Harvard Sch Publ Hlth, Dept Hlth Policy & Management, Boston, MA USA
[5] Brigham & Womens Hosp, Div Aging, Boston, MA 02115 USA
[6] Brigham & Womens Hosp, Div Gastroenterol, Boston, MA 02115 USA
[7] Dana Farber Canc Inst, Div Populat Sci, Boston, MA 02115 USA
[8] Harvard Univ, Sch Med, Boston, MA USA