1. Department of Community Health Nursing, Shimane University Faculty of Medicine, Izumo, Shimane, 693-8501, Japan
2. Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo, 173-015, Japan
3. Faculty of Nursing, St. Mary's College, Kurume, Fukuoka, 830-8558, Japan
4. Institute of Health Science, Kyushu University, Kasuga, Fukuoka 816-8580, Japan