1. Section of Gastroenterology and Hepatology Michael E. DeBakey VA Medical Center and Baylor College of Medicine Houston TX
2. Clinical Epidemiology and Comparative Effectiveness Program Section of Health Services Research (IQuESt) Michael E. DeBakey VA Medical Center and Baylor College of Medicine Houston TX
3. Department of Biostatistics University of Texas MD Anderson Cancer Center Houston TX
4. Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine Houston TX
5. Section of Epidemiology and Population Sciences Baylor College of Medicine Houston TX
6. Texas Medical Center Digestive Disease Center Houston TX