1. VA Portland Health Care System, Portland, OR, USA
2. Division of General Internal Medicine and Geriatrics, Oregon Health & Science University, Portland, OR, USA
3. Department of Sociology, Portland State University, Portland, OR, USA
4. School of Social Work, Portland State University, Portland, OR, USA
5. School of Public Health, Oregon Health & Science University and Portland State University, Portland, OR, USA
6. Department of Sociology, University of California, Los Angeles, CA, USA