1. General Medicine Service, VA Puget Sound Health Care System, Seattle, Washington;
2. Department of Medicine, University of Washington, Seattle, Washington;
3. Epidemiologic Research and Information Center, VA Puget Sound Health Care System, Seattle, Washington;
4. Health Services Research & Development, VA Puget Sound Health Care System, Seattle, Washington;
5. Department of Epidemiology and Health Services, University of Washington, Seattle, Washington.