1. Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
2. Department of Palliative Medicine, Osaka University Graduate School of Medicine, Suita, Japan
3. Yamato Clinic, Sakuragawa, Japan
4. Center for Palliative and Supportive Care, University of Tsukuba Hospital, Tsukuba, Japan
5. Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
6. Department of Palliative Medicine, Tsukuba Medical Center Hospital, Tsukuba, Japan