1. Drexel University School of Public Health, Philadelphia, Pennsylvania.
2. Oregon State University, Corvallis, Oregon.
3. Fred Hutchinson Cancer Research Center and the Group Health Research Institute, Seattle, Washington.
4. University of Hawaii John A. Burns School of Medicine, Honolulu, Hawaii.
5. Atlanta VA Medical Center, Decatur, Georgia, and Department of Medicine, Emory University, Atlanta, Georgia.
6. Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.