Chapter 4 Frailty and specific diseases. (12th February 2020) - Sugimoto, Ken; Rakugi, Hiromi; Kojima, Taro; Ishii, Shinya; Akishita, Masahiro; Tamura, Yoshiaki; Araki, Atsushi; Kozaki, Koichi; Senda, Kazuyoshi; Fukuoka, Hideki; Satake, Shosuke; Arai, Hidenori