1. Department of Epidemiology; Rollins School of Public Health; Emory University; Atlanta Georgia
2. Division of Digestive Diseases; Department of Medicine; School of Medicine; Emory University; Atlanta Georgia
3. Consultants in Gastroenterology; West Columbia South Carolina
4. Department of Epidemiology; Geisel School of Medicine at Dartmouth; Lebanon New Hampshire
5. Winship Cancer Institute; Emory University; Atlanta Georgia
6. Department of Medicine; Geisel School of Medicine at Dartmouth; Lebanon New Hampshire
7. University of North Carolina at Chapel Hill; Chapel Hill North Carolina