1James Everhart, Chief, Epidemiology and Clinical Trials Branch, Division of Digestive Diseases and Nutrition, Natcher Building, Room 6AN-12J, 45 Center Drive MSC 6600, Bethesda, MD 20892-6600.
2NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
3University of Pittsburgh Graduate School of Public Health;
4University of Nebraska Medical Center
5Mayo Clinic and Foundation.
6University of California at San Francisco