1. UN . World population prospects 2019. New York: United Nations Population Division, 2019. https://population.un.org/wpp/Download/Standard/Population/
2. The coming acceleration of global population ageing
3. The world report on ageing and health: a policy framework for healthy ageing;Beard;The Lancet,2016
4. Measuring population ageing: an analysis of the global burden of disease study 2017;Chang;Lancet Public Health,2019
5. Souza DLB , Oliveras-Fabregas A , Minobes-Molina E , et al . Trends of multimorbidity in 15 European countries: a population-based study in community-dwelling adults aged 50 and over. BMC Public Health 2021;21:76. doi:10.1186/s12889-020-10084-x