1. Cabinet Office. Japan. Annual report on the ageing society; 2020. (in Japanese) [cited Jan 10 2022]. Available from: 〈https://www8.cao.go.jp/kourei/whitepaper/index-w.html〉.
2. Ministry of Finance. Japan. Nihon Zaisei Wo Kangaeru. (in Japanese) (accessed 2022 Jan 10). Available from: 〈https://www.mof.go.jp/zaisei/current-situation/index.html〉.
3. Social security-related budget. 2020 (in Japanese);Bou;Rippou Chousa,2020
4. OECD. OECD health statistics; 2021 [cited Jan 10 2022]. Available from: 〈https://data.oecd.org/healthcare/length-of-hospital-stay.htm〉.
5. Nutritional factors affecting length of hospital stay in patients undergoing cardiovascular surgery;Yasuda;Pharmazie,2019