1 Division of Nursing Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima 734-8553, Japan. Electronic address: jkako-tky@umin.ac.jp.
2 Department of Palliative Medicine, National Cancer Center Hospital, Chuoku, Tokyo, Japan.
3 Division of Nursing Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima 734-8553, Japan.