Changes in life expectancy and life span equality during the COVID-19 epidemic in Japan up to 2022

Abstract

Objectives: To evaluate the impact of COVID-19 on life expectancy in Japan through demographic analyses. Methods: We evaluated the relationship between the life expectancy gap from 2020-21 and 2021-22 and COVID-19 epidemic size at prefectural level. We also conducted age- and cause-specific decomposition of life expectancy change. Trends in life span equality from 2000-22 were evaluated at the national level. Results: Prefectural analysis of 2021-22 life expectancy change and annual per-population COVID-19 cases, person-days in intensive care, and reported COVID-19 deaths showed no significant correlations, unlike our analysis from 2020-21. However, decomposition analysis revealed substantial life expectancy shortening attributable to the population over 35 years old. It also showed large increases in causes of death such as cardiovascular or respiratory disorders as well as COVID-19. Whole-population life span equality declined in 2020 but increased in 2021 and 2022 despite the shorter life expectancy. Conclusions: Discrepancy between life expectancy change and COVID-19 statistics in 2022 suggests the growing ascertainment bias of COVID-19. The increased contribution of cardiovascular disorders to life expectancy shortening is an alarming sign for the future. Life span equality changes in 2021 and 2022 can probably be attributed to increased mortality among older people.