Background: We compared modal age at death and lifespan variation at shared life expectancy level across East Asian countries and between East Asian and selected non–East Asian countries. In addition, age- and cause-specific contributions to differences in the modal age at death and lifespan variation to global average values were analyzed.

Methods: Data from the Global Burden of Disease 2023 were used to obtain sex-specific population and cause-specific death numbers in 5-year age groups (0, 1–4, …, 95+) for six East Asian countries and 37 non-East Asian countries from 1980 to 2023. Sex- and year-specific life tables were constructed by country. Abridged probabilities of dying were interpolated into single-year probabilities of dying. The CoDe 2.1 model was fitted, and the estimated parameters were used to estimate the modal age at death, lifespan variation indicators, and life expectancy at birth.

Results: During the entire study period, the modal age at death generally increased, and lifespan variation decreased across the East Asian countries, although the specific patterns varied by country. Japan, the Republic of Korea, and China exhibited similar modal age at death and lifespan variation at shared levels of life expectancy for both sexes. However, Taiwanese males showed relatively higher values for both the modal age at death and lifespan variation than in other countries. Although both Mongolia and the Democratic Republic of Korea experienced fluctuations in life expectancy during the 1990s, their patterns differed. In Mongolia, declines in life expectancy were accompanied by decreases in both the modal age at death and lifespan variation. In the Democratic Republic of Korea, however, the modal age at death showed little change, while lifespan variation increased. Comparisons of the modal age at death and lifespan variation in East Asian countries at shared levels of life expectancy with 37 non–East Asian countries, as well as decomposition analyses, are currently underway.

Conclusion: Across the study period, East Asian countries showed an upward trend in the modal age at death and a downward trend in lifespan variation, although detailed patterns differed by country. Examining the modal age at death and lifespan variation at shared levels of life expectancy not only provides a more nuanced understanding of historical trends in mortality patterns but also helps inform projections of future trends.