1 Division of Nursing Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi, Minami-ku, Hiroshima 734-8553, Japan. Electronic address: jkako-tky@umin.ac.jp.
2 Department of Palliative Medicine, National Cancer Center Hospital, Chuo-ku, Tokyo, Japan.
3 Japanese Red Cross Kyushu International College of Nursing, Munakata, Fukuoka, Japan.