1. Birmingham/Atlanta VA Geriatric Research, Education, and Clinical Center, Center for Aging, Division of Gerontology and Geriatric Medicine, University of Alabama at Birmingham, AL, USA.
2. Center for Aging, Division of Gerontology and Geriatric Medicine, University of Alabama at Birmingham, AL, USA.
3. Department of Epidemiology, Center for Aging, University of Alabama at Birmingham, AL, USA.