1 Section of Gastroenterology and Hepatology and Clinical Epidemiology and Comparative Effectiveness Program in the Health Services Research, Michael E. DeBakey VA Medical Center, Baylor College of Medicine, 2002 Holcombe Blvd (MS152), Houston, TX, 77030, USA. ynataraj@bcm.edu.
2 Section of Gastroenterology and Hepatology and Clinical Epidemiology and Comparative Effectiveness Program in the Health Services Research, Michael E. DeBakey VA Medical Center, Baylor College of Medicine, 2002 Holcombe Blvd (MS152), Houston, TX, 77030, USA.
3 Clinical Epidemiology and Comparative Effectiveness Program, Section of Health Services Research (IQuESt), Michael E. DeBakey VA Medical Center, Baylor College of Medicine, Houston, TX, USA.
4 Texas Medical Center Digestive Disease Center, Houston, TX, USA.
5 Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine, Houston, TX, USA.