Long-term mortality rate changes and inverse patterns for pandemic and post-pandemic excess mortality
- 1Stanford University School of Medicine
Abstract
The COVID-19 pandemic and pandemic response may have long-term consequences. The cumulative impact may be better appraised when post-pandemic years are also considered. For 38 populations with reliable death registration data, we estimated excess deaths for 2020-2025 with granular age stratification. One model (Fa) compared deaths against the mean of 2017-2019. Three other trend models considered changes in mortality rates after 2003 (or after a country reached $20,000 per capita income) factoring trend-of-trends (TTa), including shrinkage (STTa), and factoring also the 2024-2025 data for trend-of-trends calculation (STTa). Slopes (weighted mean -0.62%/year in 2019) and slopes-of-slopes (weighted mean +0.104%/year{superscript 2}) for age-stratified mortality rates were highly heterogeneous across populations. On model average, 4 populations (Luxembourg, Ireland, Sweden, New Zealand) had cumulative death deficits during 2020-2025, while another 6 (Chile, Bulgaria, Japan, Greece, Slovakia, Italy) had >4% excess deaths. Differences were more prominent during 2020-2023, while 33/38 countries had death deficits in 2024-2025. Total 2020-2025 excess deaths were 0.92-2.49 million (2020-2023: 1.99 -2.88 million; 2024-2025: a deficit of 0.39-1.08 million). Lack of age stratification and use of unchanged linear trends for the baseline (as in Lee-Carter modeling) grossly biased excess death estimates upwards. Socioeconomically more vulnerable populations had higher pandemic deaths, but a more pronounced post-pandemic death deficit. Excess death estimates require careful consideration of changing population age structure and long-term mortality trajectories. Post-pandemic deficits, especially in more vulnerable populations, may reflect pandemic deaths of people with modest life expectancy, paid off in 2024-2025.
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BibTeX
@misc{ioannidis2026longterm,
title = {{Long-term mortality rate changes and inverse patterns for pandemic and post-pandemic excess mortality}},
author = {J. Ioannidis and M. Levitt},
howpublished = {medRxiv},
year = {2026},
month = aug,
doi = {10.64898/2026.08.14.26360482},
url = {https://www.medrxiv.org/content/10.64898/2026.08.14.26360482v2},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Long-term mortality rate changes and inverse patterns for pandemic and post-pandemic excess mortality
AU - J. Ioannidis
AU - M. Levitt
PY - 2026
DA - 2026/08/14
PB - medRxiv
DO - 10.64898/2026.08.14.26360482
UR - https://www.medrxiv.org/content/10.64898/2026.08.14.26360482v2
AB - The COVID-19 pandemic and pandemic response may have long-term consequences. The cumulative impact may be better appraised when post-pandemic years are also considered. For 38 populations with reliable death registration data, we estimated excess deaths for 2020-2025 with granular age stratification. One model (Fa) compared deaths against the mean of 2017-2019. Three other trend models considered changes in mortality rates after 2003 (or after a country reached $20,000 per capita income) factoring trend-of-trends (TTa), including shrinkage (STTa), and factoring also the 2024-2025 data for trend-of-trends calculation (STTa). Slopes (weighted mean -0.62%/year in 2019) and slopes-of-slopes (weighted mean +0.104%/year{superscript 2}) for age-stratified mortality rates were highly heterogeneous across populations. On model average, 4 populations (Luxembourg, Ireland, Sweden, New Zealand) had cumulative death deficits during 2020-2025, while another 6 (Chile, Bulgaria, Japan, Greece, Slovakia, Italy) had >4% excess deaths. Differences were more prominent during 2020-2023, while 33/38 countries had death deficits in 2024-2025. Total 2020-2025 excess deaths were 0.92-2.49 million (2020-2023: 1.99 -2.88 million; 2024-2025: a deficit of 0.39-1.08 million). Lack of age stratification and use of unchanged linear trends for the baseline (as in Lee-Carter modeling) grossly biased excess death estimates upwards. Socioeconomically more vulnerable populations had higher pandemic deaths, but a more pronounced post-pandemic death deficit. Excess death estimates require careful consideration of changing population age structure and long-term mortality trajectories. Post-pandemic deficits, especially in more vulnerable populations, may reflect pandemic deaths of people with modest life expectancy, paid off in 2024-2025.
ER -