1.Characteristics and trends of severe/critical COVID-19cases in the Republic of Korea (January 2020 to August 2023)
Se-Jin JEONG ; Shin Young PARK ; Boyeong RYU ; Misuk AN ; Jin-Hwan JEON ; So Young CHOI ; Seong-Sun KIM
Osong Public Health and Research Perspectives 2025;16(1):81-88
Objectives:
We analyzed the demographic and clinical characteristics of patients diagnosedwith coronavirus disease 2019 (COVID-19), focusing specifically on severe/critical cases, andassessed the trends and rates of severity and fatality among these patients in the Republic of Korea.
Methods:
Clinical data on patients with COVID-19 from January 20, 2020 to August 30, 2023were collected from the Korea Disease Control and Prevention Agency’s database. We identified patients who progressed to severe/critical conditions and analyzed their demographic and clinical profiles. Severity and fatality rates were calculated and compared annually to track thedisease progression over time.
Results:
During the surveillance period, 34,572,554 COVID-19 cases were confirmed, among whom 38,112 (0.11%) progressed to severe/critical conditions. Most severe/critical cases occurred in individuals aged ≥60 years, with a notable increase in patients aged ≥80 years from 2022.The overall severity rate was 0.19%, with a fatality rate of 0.10%. However, the severity of cases gradually diminished during the study period. In 2022, the severity and fatality rates decreased to 0.14% and 0.09%, respectively. In 2023, while the severity rate remained stable at 0.15%, thefatality rate further decreased to 0.06%. Notably, throughout the study period, individuals aged ≥80 years had a significantly higher severity rate (2.44%), with a fatality rate of 1.75%.
Conclusion
These findings underscore the importance of prioritizing protection and management strategies for older adults and high-risk groups to mitigate the impact ofCOVID-19. Continued surveillance and analysis are essential to effectively control COVID-19 and minimize its burden on public health.
2.Characteristics and trends of severe/critical COVID-19cases in the Republic of Korea (January 2020 to August 2023)
Se-Jin JEONG ; Shin Young PARK ; Boyeong RYU ; Misuk AN ; Jin-Hwan JEON ; So Young CHOI ; Seong-Sun KIM
Osong Public Health and Research Perspectives 2025;16(1):81-88
Objectives:
We analyzed the demographic and clinical characteristics of patients diagnosedwith coronavirus disease 2019 (COVID-19), focusing specifically on severe/critical cases, andassessed the trends and rates of severity and fatality among these patients in the Republic of Korea.
Methods:
Clinical data on patients with COVID-19 from January 20, 2020 to August 30, 2023were collected from the Korea Disease Control and Prevention Agency’s database. We identified patients who progressed to severe/critical conditions and analyzed their demographic and clinical profiles. Severity and fatality rates were calculated and compared annually to track thedisease progression over time.
Results:
During the surveillance period, 34,572,554 COVID-19 cases were confirmed, among whom 38,112 (0.11%) progressed to severe/critical conditions. Most severe/critical cases occurred in individuals aged ≥60 years, with a notable increase in patients aged ≥80 years from 2022.The overall severity rate was 0.19%, with a fatality rate of 0.10%. However, the severity of cases gradually diminished during the study period. In 2022, the severity and fatality rates decreased to 0.14% and 0.09%, respectively. In 2023, while the severity rate remained stable at 0.15%, thefatality rate further decreased to 0.06%. Notably, throughout the study period, individuals aged ≥80 years had a significantly higher severity rate (2.44%), with a fatality rate of 1.75%.
Conclusion
These findings underscore the importance of prioritizing protection and management strategies for older adults and high-risk groups to mitigate the impact ofCOVID-19. Continued surveillance and analysis are essential to effectively control COVID-19 and minimize its burden on public health.
3.Age-Stratified Risk of Severe COVID-19 for People With Disabilities in Korea:Nationwide Study Considering Disability Type
Boyeong RYU ; Hoyeon JANG ; Jaiyong KIM ; Sung-il CHO ; Seong-Sun KIM
Journal of Korean Medical Science 2025;40(7):e37-
Background:
Understanding disparities in severe coronavirus disease 2019 (COVID-19) outcomes between people with disabilities (PwD) and people without disabilities (PwoD) is crucial, particularly when considering the heterogeneity within PwD and age differences.This study aimed to compare severe COVID-19 outcomes including deaths between PwD and PwoD with analyses stratified by age group and further examined by disability type.
Methods:
This retrospective, population-based cohort study used linked data from national COVID-19 cases and health insurance for individuals aged ≥ 19 years with COVID-19 from January 2020 to October 2022 in the Republic of Korea. Severe outcomes included severe cases and deaths, with logistic regression analysis of the risk disparities between PwD and PwoD based on age group and disability types. The subgroup analysis considered epidemic periods, accounting for the severe acute respiratory syndrome coronavirus 2 variant circulation.
Results:
The risk of severe COVID-19 outcomes and deaths among PwD varied by age and disability type. While severe outcomes were most prevalent in the older age groups for both PwD and PwoD, younger PwD faced a markedly higher risk—up to eightfold—compared to PwoD. The risk of disability status was greater than that of comorbidities in the 19–39 age group. Among disability types, individuals with internal organs-related and intellectual disabilities showed higher risk disparities with PwoD in severe outcomes than other types of disabilities. Throughout the pandemic, the disparity in death risk remained similar, with a slight increase in disparity during the omicron period for all severe outcomes in the age groups 19–39 and 40–64 years.
Conclusion
Prioritizing younger PwD, along with older age groups and people with comorbidities, is crucial in addressing public health crises. Risk-based prioritization is important to reduce overall risk. This includes prioritizing people with nternal organs-related and intellectural disabilities, who face higher health risks among PwD during a pandemic when resources are limited and time is of the essence.
4.Characteristics and trends of severe/critical COVID-19cases in the Republic of Korea (January 2020 to August 2023)
Se-Jin JEONG ; Shin Young PARK ; Boyeong RYU ; Misuk AN ; Jin-Hwan JEON ; So Young CHOI ; Seong-Sun KIM
Osong Public Health and Research Perspectives 2025;16(1):81-88
Objectives:
We analyzed the demographic and clinical characteristics of patients diagnosedwith coronavirus disease 2019 (COVID-19), focusing specifically on severe/critical cases, andassessed the trends and rates of severity and fatality among these patients in the Republic of Korea.
Methods:
Clinical data on patients with COVID-19 from January 20, 2020 to August 30, 2023were collected from the Korea Disease Control and Prevention Agency’s database. We identified patients who progressed to severe/critical conditions and analyzed their demographic and clinical profiles. Severity and fatality rates were calculated and compared annually to track thedisease progression over time.
Results:
During the surveillance period, 34,572,554 COVID-19 cases were confirmed, among whom 38,112 (0.11%) progressed to severe/critical conditions. Most severe/critical cases occurred in individuals aged ≥60 years, with a notable increase in patients aged ≥80 years from 2022.The overall severity rate was 0.19%, with a fatality rate of 0.10%. However, the severity of cases gradually diminished during the study period. In 2022, the severity and fatality rates decreased to 0.14% and 0.09%, respectively. In 2023, while the severity rate remained stable at 0.15%, thefatality rate further decreased to 0.06%. Notably, throughout the study period, individuals aged ≥80 years had a significantly higher severity rate (2.44%), with a fatality rate of 1.75%.
Conclusion
These findings underscore the importance of prioritizing protection and management strategies for older adults and high-risk groups to mitigate the impact ofCOVID-19. Continued surveillance and analysis are essential to effectively control COVID-19 and minimize its burden on public health.
5.Age-Stratified Risk of Severe COVID-19 for People With Disabilities in Korea:Nationwide Study Considering Disability Type
Boyeong RYU ; Hoyeon JANG ; Jaiyong KIM ; Sung-il CHO ; Seong-Sun KIM
Journal of Korean Medical Science 2025;40(7):e37-
Background:
Understanding disparities in severe coronavirus disease 2019 (COVID-19) outcomes between people with disabilities (PwD) and people without disabilities (PwoD) is crucial, particularly when considering the heterogeneity within PwD and age differences.This study aimed to compare severe COVID-19 outcomes including deaths between PwD and PwoD with analyses stratified by age group and further examined by disability type.
Methods:
This retrospective, population-based cohort study used linked data from national COVID-19 cases and health insurance for individuals aged ≥ 19 years with COVID-19 from January 2020 to October 2022 in the Republic of Korea. Severe outcomes included severe cases and deaths, with logistic regression analysis of the risk disparities between PwD and PwoD based on age group and disability types. The subgroup analysis considered epidemic periods, accounting for the severe acute respiratory syndrome coronavirus 2 variant circulation.
Results:
The risk of severe COVID-19 outcomes and deaths among PwD varied by age and disability type. While severe outcomes were most prevalent in the older age groups for both PwD and PwoD, younger PwD faced a markedly higher risk—up to eightfold—compared to PwoD. The risk of disability status was greater than that of comorbidities in the 19–39 age group. Among disability types, individuals with internal organs-related and intellectual disabilities showed higher risk disparities with PwoD in severe outcomes than other types of disabilities. Throughout the pandemic, the disparity in death risk remained similar, with a slight increase in disparity during the omicron period for all severe outcomes in the age groups 19–39 and 40–64 years.
Conclusion
Prioritizing younger PwD, along with older age groups and people with comorbidities, is crucial in addressing public health crises. Risk-based prioritization is important to reduce overall risk. This includes prioritizing people with nternal organs-related and intellectural disabilities, who face higher health risks among PwD during a pandemic when resources are limited and time is of the essence.
6.Age-Stratified Risk of Severe COVID-19 for People With Disabilities in Korea:Nationwide Study Considering Disability Type
Boyeong RYU ; Hoyeon JANG ; Jaiyong KIM ; Sung-il CHO ; Seong-Sun KIM
Journal of Korean Medical Science 2025;40(7):e37-
Background:
Understanding disparities in severe coronavirus disease 2019 (COVID-19) outcomes between people with disabilities (PwD) and people without disabilities (PwoD) is crucial, particularly when considering the heterogeneity within PwD and age differences.This study aimed to compare severe COVID-19 outcomes including deaths between PwD and PwoD with analyses stratified by age group and further examined by disability type.
Methods:
This retrospective, population-based cohort study used linked data from national COVID-19 cases and health insurance for individuals aged ≥ 19 years with COVID-19 from January 2020 to October 2022 in the Republic of Korea. Severe outcomes included severe cases and deaths, with logistic regression analysis of the risk disparities between PwD and PwoD based on age group and disability types. The subgroup analysis considered epidemic periods, accounting for the severe acute respiratory syndrome coronavirus 2 variant circulation.
Results:
The risk of severe COVID-19 outcomes and deaths among PwD varied by age and disability type. While severe outcomes were most prevalent in the older age groups for both PwD and PwoD, younger PwD faced a markedly higher risk—up to eightfold—compared to PwoD. The risk of disability status was greater than that of comorbidities in the 19–39 age group. Among disability types, individuals with internal organs-related and intellectual disabilities showed higher risk disparities with PwoD in severe outcomes than other types of disabilities. Throughout the pandemic, the disparity in death risk remained similar, with a slight increase in disparity during the omicron period for all severe outcomes in the age groups 19–39 and 40–64 years.
Conclusion
Prioritizing younger PwD, along with older age groups and people with comorbidities, is crucial in addressing public health crises. Risk-based prioritization is important to reduce overall risk. This includes prioritizing people with nternal organs-related and intellectural disabilities, who face higher health risks among PwD during a pandemic when resources are limited and time is of the essence.
7.Characteristics and trends of severe/critical COVID-19cases in the Republic of Korea (January 2020 to August 2023)
Se-Jin JEONG ; Shin Young PARK ; Boyeong RYU ; Misuk AN ; Jin-Hwan JEON ; So Young CHOI ; Seong-Sun KIM
Osong Public Health and Research Perspectives 2025;16(1):81-88
Objectives:
We analyzed the demographic and clinical characteristics of patients diagnosedwith coronavirus disease 2019 (COVID-19), focusing specifically on severe/critical cases, andassessed the trends and rates of severity and fatality among these patients in the Republic of Korea.
Methods:
Clinical data on patients with COVID-19 from January 20, 2020 to August 30, 2023were collected from the Korea Disease Control and Prevention Agency’s database. We identified patients who progressed to severe/critical conditions and analyzed their demographic and clinical profiles. Severity and fatality rates were calculated and compared annually to track thedisease progression over time.
Results:
During the surveillance period, 34,572,554 COVID-19 cases were confirmed, among whom 38,112 (0.11%) progressed to severe/critical conditions. Most severe/critical cases occurred in individuals aged ≥60 years, with a notable increase in patients aged ≥80 years from 2022.The overall severity rate was 0.19%, with a fatality rate of 0.10%. However, the severity of cases gradually diminished during the study period. In 2022, the severity and fatality rates decreased to 0.14% and 0.09%, respectively. In 2023, while the severity rate remained stable at 0.15%, thefatality rate further decreased to 0.06%. Notably, throughout the study period, individuals aged ≥80 years had a significantly higher severity rate (2.44%), with a fatality rate of 1.75%.
Conclusion
These findings underscore the importance of prioritizing protection and management strategies for older adults and high-risk groups to mitigate the impact ofCOVID-19. Continued surveillance and analysis are essential to effectively control COVID-19 and minimize its burden on public health.
8.Age-Stratified Risk of Severe COVID-19 for People With Disabilities in Korea:Nationwide Study Considering Disability Type
Boyeong RYU ; Hoyeon JANG ; Jaiyong KIM ; Sung-il CHO ; Seong-Sun KIM
Journal of Korean Medical Science 2025;40(7):e37-
Background:
Understanding disparities in severe coronavirus disease 2019 (COVID-19) outcomes between people with disabilities (PwD) and people without disabilities (PwoD) is crucial, particularly when considering the heterogeneity within PwD and age differences.This study aimed to compare severe COVID-19 outcomes including deaths between PwD and PwoD with analyses stratified by age group and further examined by disability type.
Methods:
This retrospective, population-based cohort study used linked data from national COVID-19 cases and health insurance for individuals aged ≥ 19 years with COVID-19 from January 2020 to October 2022 in the Republic of Korea. Severe outcomes included severe cases and deaths, with logistic regression analysis of the risk disparities between PwD and PwoD based on age group and disability types. The subgroup analysis considered epidemic periods, accounting for the severe acute respiratory syndrome coronavirus 2 variant circulation.
Results:
The risk of severe COVID-19 outcomes and deaths among PwD varied by age and disability type. While severe outcomes were most prevalent in the older age groups for both PwD and PwoD, younger PwD faced a markedly higher risk—up to eightfold—compared to PwoD. The risk of disability status was greater than that of comorbidities in the 19–39 age group. Among disability types, individuals with internal organs-related and intellectual disabilities showed higher risk disparities with PwoD in severe outcomes than other types of disabilities. Throughout the pandemic, the disparity in death risk remained similar, with a slight increase in disparity during the omicron period for all severe outcomes in the age groups 19–39 and 40–64 years.
Conclusion
Prioritizing younger PwD, along with older age groups and people with comorbidities, is crucial in addressing public health crises. Risk-based prioritization is important to reduce overall risk. This includes prioritizing people with nternal organs-related and intellectural disabilities, who face higher health risks among PwD during a pandemic when resources are limited and time is of the essence.
9.Characteristics and trends of severe/critical COVID-19cases in the Republic of Korea (January 2020 to August 2023)
Se-Jin JEONG ; Shin Young PARK ; Boyeong RYU ; Misuk AN ; Jin-Hwan JEON ; So Young CHOI ; Seong-Sun KIM
Osong Public Health and Research Perspectives 2025;16(1):81-88
Objectives:
We analyzed the demographic and clinical characteristics of patients diagnosedwith coronavirus disease 2019 (COVID-19), focusing specifically on severe/critical cases, andassessed the trends and rates of severity and fatality among these patients in the Republic of Korea.
Methods:
Clinical data on patients with COVID-19 from January 20, 2020 to August 30, 2023were collected from the Korea Disease Control and Prevention Agency’s database. We identified patients who progressed to severe/critical conditions and analyzed their demographic and clinical profiles. Severity and fatality rates were calculated and compared annually to track thedisease progression over time.
Results:
During the surveillance period, 34,572,554 COVID-19 cases were confirmed, among whom 38,112 (0.11%) progressed to severe/critical conditions. Most severe/critical cases occurred in individuals aged ≥60 years, with a notable increase in patients aged ≥80 years from 2022.The overall severity rate was 0.19%, with a fatality rate of 0.10%. However, the severity of cases gradually diminished during the study period. In 2022, the severity and fatality rates decreased to 0.14% and 0.09%, respectively. In 2023, while the severity rate remained stable at 0.15%, thefatality rate further decreased to 0.06%. Notably, throughout the study period, individuals aged ≥80 years had a significantly higher severity rate (2.44%), with a fatality rate of 1.75%.
Conclusion
These findings underscore the importance of prioritizing protection and management strategies for older adults and high-risk groups to mitigate the impact ofCOVID-19. Continued surveillance and analysis are essential to effectively control COVID-19 and minimize its burden on public health.
10.Estimating Excess Mortality During the COVID-19 Pandemic Between 2020–2022 in Korea
Minjeong JANG ; Soyoung KIM ; Sunhwa CHOI ; Boyeong RYU ; So Young CHOI ; Siwon CHOI ; Misuk AN ; Seong-Sun KIM
Journal of Korean Medical Science 2024;39(40):e267-
Background:
The persistent coronavirus disease 2019 (COVID-19) pandemic has had direct and indirect effects on mortality, making it essential to analyze excess mortality to fully understand the impact of the pandemic. In this study, we constructed a mathematical model using number of deaths from Statistics Korea and analyzed excess mortality between 2020 and 2022 according to age, sex, and dominant severe acute respiratory syndrome coronavirus 2 variant period.
Methods:
Number of all-cause deaths between 2010 and 2022 were obtained from the annual cause-of-death statistics provided by Statistics Korea. COVID-19 mortality data were acquired from the Korea Disease Control and Prevention Agency. A multivariate linear regression model with seasonal effect, stratified by sex and age, was used to estimate the number of deaths in the absence of COVID-19. The estimated excess mortality rate was calculated.
Results:
Excess mortality was not significant between January 2020 and October 2021.However, it started to increase monthly from November 2021 and reached its highest point during the omicron-dominant period. Specifically, in March and April 2022, during the omicron BA.1/BA.2-dominant period, the estimated median values for excess mortality were the highest at 17,634 and 11,379, respectively. Both COVID-19-related deaths and excess mortality increased with age. A notable increase in excess mortality was observed in individuals aged ≥ 65 years. In the context of excess mortality per 100,000 population based on the estimated median values in March 2022, the highest numbers were found among males and females aged ≥ 85 years at 1,048 and 910, respectively.
Conclusion
This study revealed that the prolonged COVID-19 pandemic coupled with its high transmissibility not only increased COVID-19-related deaths but also had a significant impact on overall mortality rates, especially in the elderly. Therefore, it is crucial to concentrate healthcare resources and services on the elderly and ensure continued access to healthcare services during pandemics. Establishing an excess mortality monitoring system in the early stages of a pandemic is necessary to understand the impact of infectious diseases on mortality and effectively evaluate pandemic response policies.

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