The World Health Organization declared COVID-19 no longer a global health emergency on 5^th May 2023; however, the impact of COVID-19 on life expectancy throughout the pandemic period is not clear. This study aimed to quantify and decompose the changes in life expectancy during 2019–2023 and corresponding age and gender disparities in 27 countries. Data were sourced from the Human Mortality Database, the World Population Prospects 2022 and the United Kingdom's Office for National Statistics. Life expectancy was estimated using the abridged life table method, while differentials of life expectancies were decomposed using the age-decomposition algorithm. There was an overall reduction in life expectancy at age 5 among the 27 countries in 2020. Life expectancy rebounded in Western, Northern and Southern Europe in 2021 but further decreased in the United States, Chile and Eastern Europe in the same year. In 2022 and after, lost life expectancy years in the United States, Chile and Eastern Europe were slowly regained; however, as of 7^th May 2023, life expectancy in 22 of the 27 countries had not fully recovered to its pre-pandemic level. The reduced life expectancy in 2020 was mainly driven by reduced life expectancy at age 65+, while that in subsequent years was mainly driven by reduced life expectancy at age 45–74. Women experienced a lower reduction in life expectancy at most ages but a greater reduction at age 85+. The pandemic has caused substantial short-term mortality variations during 2019–2023 in the 27 countries studied. Although most of the 27 countries experienced increased life expectancy after 2022, life expectancy in 22 countries still has not entirely regained its pre-pandemic level by May 2023. Threats of COVID-19 are more prominent for older adults and men, but special attention is needed for women aged 85+ years.

The expected year-on-year intrinsic mortality variations/changes are largely overlooked in the existing research when estimating the effect of the COVID-19 pandemic on mortality patterns. To fill this gap, this study provides a new assessment of the loss of life expectancy caused by COVID-19 in 27 countries considering both the actual and the expected changes in life expectancy between 2019 and 2020. Life expectancy in 2020 and the expected life expectancy in the absence of COVID-19 are estimated using the Lee-Carter model and data primarily from the Human Mortality Database. The results show that life expectancy in 21 of the 27 countries was expected to increase in 2020 had COVID-19 not occurred. By considering the expected mortality changes between 2019 and 2020, the study shows that, on average, the loss of life expectancy among the 27 countries in 2020 amounted to 1.33 year (95% CI 1.29–1.37) at age 15 and 0.91 years (95% CI 0.88–0.94) at age 65. Our results suggest that if the year-on-year intrinsic variations/changes in mortality were considered, the effects of COVID-19 on mortality are more profound than previously understood. This is particularly prominent for countries experiencing greater life expectancy increase in recent years.

Migrant health constitutes an important public health issue; however, variations in the ‘healthy migrant effect’ among migrants of different nativity are not adequately understood. To fill this gap, this study examines the life expectancy (LE) and healthy life expectancy (HLE) of the Australian-born population and eight major migrant groups in Australia for 2006, 2011 and 2016. The results show that compared with the Australian-born population, the foreign-born population overall had a higher LE and HLE but a lower HLE/LE ratio. Considerable variations in migrant health status according to nativity were also observed. Specifically, migrants from South Africa, Britain and Germany exhibited a similar or higher LE, HLE and HLE/LE ratio, while those from China, India, Italy and Greece had a higher LE but a significantly lower HLE/LE ratio compared with the Australian-born population. Lebanese migrants were the only group who experienced an unchanging LE and a declining HLE from 2006 to 2016. These notable differences in migrants' health outcomes with respect to nativity may be explained by the sociocultural differences between the origin and host countries and the different extents of migration selectivity of different migrant groups. Targeted countermeasures such as improving the quality of life of migrants from culturally diverse backgrounds or with negative migration experiences are suggested.