[1] Univ Tokyo, Sch Publ Hlth, Dept Hlth & Social Behav, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan
[2] Canc Scan, Shibuya Ku, Tokyo, Japan
[3] Chiba Univ, Ctr Prevent Med Sci, Chiba, Japan
[4] Natl Ctr Geriatr & Gerontol, Ctr Gerontol & Social Sci, Nagoya, Aichi, Japan
[5] Mccann Hlth Commun, Dept Publ Hlth, Minato Ku, Tokyo, Japan
[6] Harvard Univ, Sch Publ Hlth, Dept Social & Behav Sci, 665 Huntington Ave, Boston, MA 02115 USA