1. Group Health Research Institute, Seattle, Washingon.
2. Department of Epidemiology, University of Washington, Seattle, Washingon.
3. Division of Research, Kaiser Permanente Northern California, Oakland, California.
4. Meyers Primary Care Institute, Worcester, Massachusetts.
5. Lovelace Clinic Foundation, Albuquerque, New Mexico.
6. Center for Health Research, Kaiser Permanente Georgia, Atlanta, Georgia.
7. Health Partners Institute for Education and Research, Minneapolis, Minnesota.
8. Institute for Health Research, Kaiser Permanente Colorado, Denver, Colorado.
9. Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon.
10. Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.
11. Oregon Health and Science University, Portland, Oregon.