1. Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA;
2. The Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, California, USA;
3. Department of Medicine Statistics Core, David Geffen School of Medicine, University of California, Los Angeles, California, USA;
4. Office of Population Health & Accountable Care, University of California, Los Angeles, California, USA;
5. Division of Gastroenterology, Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA;
6. UCLA Kaiser Permanente Center for Health Equity, UCLA Jonsson Comprehensive Cancer Center, Los Angeles, California, USA.