[1] Yamaguchi Univ, Grad Sch Med, Fac Hlth Sci, Ube, Yamaguchi 755, Japan
[2] Ewha Womans Univ, Dept Global Hlth & Nursing, Div Nursing Sci, Coll Hlth Sci, Seoul 120750, South Korea
[3] Univ Plymouth, Fac Hlth & Human Sci, Plymouth PL4 8AA, Devon, England
[4] Univ Ryukus, Fac Hlth Sci, Urasoe, Okinawa, Japan
[5] Kawasaki Univ Med Welf, Fac Hlth & Welf, Kurashiki, Okayama, Japan