1. Department of Geriatric Medicine, National Center for Geriatrics and Gerontology, Obu-shi, Japan
2. Biostatistics Center, Kurume University Graduate School of Medicine, Kurume, Japan
3. Medical Affairs Department, Research and Development Center, Otsuka Pharmaceutical Factory, Inc., Chiyoda-ku, Japan
4. Research and Development Center, Otsuka Pharmaceutical Factory, Inc., Chiyoda-ku, Japan