1. 1Department of Epidemiology, University of Washington, Seattle, Washington.
2. 2Kaiser Permanente Washington Health Research Institute, Seattle, Washington.
3. 3Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
4. 4Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland.
5. 5Division of Research, Kaiser Permanente Northern California, Oakland, California.
6. 6Department of Gastroenterology, Kaiser Permanente San Francisco Medical Center, San Francisco, California.
7. 7Department of Medicine, Robert Wood Johnson Medical School, New Brunswick, New Jersey.
8. 8Kaiser Permanente Bernard J Tyson School of Medicine, Department of Health Systems Science, Pasadena, California.