[1] Iki Iki Clin, 9144-1 Yuki, Yuki, Ibaraki 3070001, Japan
[2] JF Oberlin Univ, Inst Gerontol, Machida, Tokyo, Japan
[3] Natl Ctr Geriatr & Gerontol, Dept Social Sci, Obu, Japan
[4] Okayama Prefectural Univ, Fac Hlth & Welf Sci, Soia, Japan
[5] Niimi Univ, Dept Community Welf, Niimi, Japan