1. 1. Vital Statistics; Trends in leading causes of death [Internet]. 2021 Available from: https://www.mhlw.go.jp/toukei/saikin/hw/jinkou/houkoku21/dl/all.pdf (in Japanese).
2. 2. Japan White Paper and Annual Reports. Ministry of Health, Labour and Welfare (in Japanese) [Internet]. Available from: https://www.mhlw.go.jp/wp/hakusyo/kousei/16/dl/all.pdf
3. 3. The Japanese Respiratory Society. Guidelines for the management adults with community-acquired pneumonia. 2000 (in Japanese).
4. 4. The Japanese Respiratory Society. Guidelines for the management adults with hospital-acquired pneumonia. 2002 (in Japanese).
5. 5. Kohno S, Imamura Y, Shindo Y, et al. Clinical practice guidelines for nursing- and healthcare-associated pneumonia (NHCAP) [complete translation]. Respir Investig 51: 103-126, 2013.