1. Department of Palliative Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
2. Department of Health Communication, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
3. Clinical Research Support Center, The University of Tokyo Hospital, Tokyo, Japan.
4. Department of Palliative and Supportive Care, Palliative Care Team, Seirei Mikatahara General Hospital, Shizuoka, Japan.