1. Kaiser Permanente Washington, Seattle
2. Kaiser Permanente Washington Health Research Institute, Seattle
3. Department of Family Medicine, University of Washington School of Medicine, Seattle
4. Department of Biostatistics, University of Washington School of Public Health, Seattle
5. Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
6. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor
7. Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon
8. Department of Health Promotion and Behavior Sciences, University of Texas School of Public Health, Houston