1. Department of Community Health, Center for Gerontology and Health Care Research, Brown University School of Medicine, Providence, Rhode Island
2. Department of Community Health, Center for Gerontology and Health Care Research, Brown University School of Medicine, Providence, Rhode Island
3. Department of Community Health, Center for Gerontology and Health Care Research, Brown University School of Medicine, Providence, Rhode Island, and Department of Sociology, Brown University, Providence, Rhode Island
4. Department of Community Health, Center for Gerontology and Health Care Research, Brown University School of Medicine, Providence, Rhode Island