1. Department of Health Promotion & Behavioral Sciences, The University of Texas Health Science Center at Houston, School of Public Health, Houston, TX, USA
2. Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
3. Department of Medicine, Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, TX, USA
4. Department of General Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
5. Department of Medicine, Section of Epidemiology and Population Sciences &Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA