1. Department of Epidemiology, Fukushima Medical University School of Medicine, 1 Hikariga-oka, Fukushima 960-1295, Japan
2. Radiation Medical Science Center for the Fukushima Health Management Survey, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan
3. Department of Public Health, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
4. Department of Social Epidemiology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
5. Department of Social Preventive Medical Sciences, Center for Preventive Medical Sciences, Chiba University, Chiba 263-8522, Japan
6. Department of Gerontological Evaluation, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan