[1] Tokyo Univ Hosp, Dept Palliat Med, Tokyo 113, Japan
[2] Tokyo Univ Pharm & Life Sci, Tokyo, Japan
[3] Kansai Med Univ, Hirakata, Osaka, Japan
[4] Hirosaki Univ, Hirosaki, Aomori, Japan
[5] Univ Tokyo, Tokyo, Japan
[6] Univ Tokyo, Interfac Initiat Informat Studies, Tokyo, Japan
[7] Nagumo Clin, Tokyo, Japan