1. Health Services Research and Development, VA Puget Sound Health Care System, Department of Veterans Affairs, Seattle, Washington
2. Department of Health Services, University of Washington, Seattle, Washington
3. Rehabilitation Research and Development, VA Puget Sound Health Care System, Department of Veterans Affairs, Seattle, Washington
4. Seattle Epidemiologic Research and Information Center, VA Puget Sound Health Care System, Department of Veterans Affairs, Seattle, Washington
5. Department of Epidemiology, University of Washington, Seattle, Washington
6. Department of Orthopedic Surgery, University of Washington, Seattle, Washington
7. Department of Medicine, University of Washington, Seattle, Washington