1. Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
2. Division of Community Medicine and Public Health Practice, School of Public Health, University of Hong Kong, Hong Kong, Republic of China
3. Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Miyagi, Japan
4. Center for Preventive Medical Sciences, Chiba University, Chiba, Japan
5. Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, Aichi, Japan