1. Department of General Medicine, Yokohama City University School of Medicine , Yokohama, Kanagawa 236-0004 , Japan
2. Department of Palliative and Supportive Care, Yokohama Minami Kyousai Hospital , Yokohama, Kanagawa 236-0004 , Japan
3. Yokohama Ekisaikai Hospital , Naka-ku, Yokohama 231-0036 , Japan
4. Department of Medical Education, Yokohama City University Hospital Yokohama City University School of Medicine , Kanazawa-ku, Yokohama 236-0004 , Japan
5. Department of Palliative and Supportive Care , Palliative Care Team, Seirei Mikatahara Hospital, Kita, Hamamatsu 433-8558 , Japan