Estimation of Excess All-cause Mortality during COVID-19 Pandemic in Korea

Abstract

Background Excess all-cause mortality is helpful to assess the full extent of the health impact, including direct and indirect deaths of coronavirus disease 2019 (COVID-19). The study aimed to estimate overall and regional excess all-cause mortality during the pandemic in Korea. Methods We obtained all-cause death data and population statistics from January 2010 to December 2020. The expected mortality in 2020 was estimated using a quasi-Poisson regression model. The model included death year, seasonal variation, cold wave (January), average death counts in the previous month, and population. Excess mortality was defined as the difference between the observed mortality and the expected mortality. Regions were classified into three areas according to the numbers of COVID-19 cases. Results There was no annual excess all-cause mortality in 2020 at the national and regional level compared to the average death for the previous ten years. The observed mortality in 2020 was 582.9 per 100,000 people, and the expected mortality was 582.3 per 100,000 people (95% confidence interval, 568.3–596.7). However, we found monthly and regional variations depending on the waves of the COVID-19 pandemic in Korea. While the mortality in August, October, and November exceeded the expected range, the mortality in September was lower than the expected range. The months in which excess deaths were identified differed by region. Conclusion Our results show that the mortality in 2020 was similar to the historical trend. However, in the era of the COVID-19 pandemic, it would be necessary to regularly investigate COVID-19-related mortality and determine its direct and indirect causes.

An ensemble learning strategy for panel time series forecasting of excess mortality during the COVID-19 pandemic

“…Figure 6 shows the same situation for the Republic of Korea, which is geographically in the vicinity of these two countries. The result from comparison of the forecast respiratory deaths and actual COVID-19 deaths for the Republic of Korea is align with the results of very recent study about estimation of excess mortality in Korea by Shin et. al., (2021), which shows that the mortality in 2020 was similar to the historical trend.…”

Global Excess Mortality during COVID-19 Pandemic: A Systematic Review and Meta-Analysis

“…A modeling study indicates that reported COVID-19 deaths are inadequate to assess the impact of the pandemic on excess mortality [ 14 ]. Excess mortality is a more comprehensive index to measure the impact of the COVID-19 pandemic on deaths, and it refers to the number of deaths from all causes during the pandemic more than what we would have expected to see under “normal” conditions, including the deaths induced by a lack of medical resources and restrictive intervention during the pandemic [ 19 , 20 , 21 ]. Moreover, excess mortality can be the reference for assessing COVID-19 deaths because further studies can estimate COVID-19 deaths based on this result by subtracting other causes of death from excess mortality (e.g., heat waves, war, etc.)…”

Inequitable distribution of excess mortality during the COVID-19 pandemic in Korea, 2020

“…This study identified a significantly larger negative excess mortality than previous studies, which estimated an excess mortality close to zero [12,13] and identified positive excess mortality [10,11]. Considering the granularity of the data used in each study, this constitutes an example of the coastline paradox wherein the length of the coastline is measured longer in smaller units.…”

“…The preliminary results from the Health Insurance Review and Assessment Service (HIRA) of South Korea reported that observed deaths were within range of the expected mortality during the COVID-19 pandemic period. [13]. The study using vital statistics also identified decreases in the overall mortality.…”