[1] Univ Calif Los Angeles, David Geffen Sch Med, Vatche & Tamar Manoukian Div Digest Dis, Dept Med, Los Angeles, CA 90095 USA
[2] Univ Calif Los Angeles, Jonathan & Karin Fielding Sch Publ Hlth, Dept Hlth Policy & Management, Los Angeles, CA USA
[3] Univ Calif Los Angeles, UCLA Kaiser Permanente Ctr Hlth Equ, Los Angeles, CA USA
[4] Univ Calif Los Angeles, Hlth Policy & Management, Los Angeles, CA USA
[5] Univ Calif Los Angeles, Jonsson Comprehens Canc Ctr, Fielding Sch Publ Hlth, Los Angeles, CA 90024 USA
[6] Univ Calif Los Angeles, Fielding Sch Publ Hlth, Los Angeles, CA USA
[7] Univ Calif Los Angeles, Los Angeles, CA USA
[8] Univ Calif Los Angeles, David Geffen Sch Med, Dept Med, Los Angeles, CA 90095 USA
[9] VA Greater Los Angeles Healthcare Syst, Div Gastroenterol Hepatol & Parenteral Nutr, Los Angeles, CA USA