Intensive Care Unit Capacity and Its Associated Risk Factors During the COVID-19 Surge in the Republic of Korea: Analysis Using Nationwide Health Claims Data

Abstract

Objective

To identify risk factors for intensive care unit (ICU) admission and mechanical ventilator usage among confirmed coronavirus disease (COVID-19) patients and estimate the effects of mitigation efforts on ICU capacity in Korea.

Patients and Methods

Data on profiles and medical history of all confirmed COVID-19 patients in the past 1 year were extracted from the Korean National Health Insurance System’s claims database to assess risk factors for ICU admission and ventilator use. We used a time-series epidemic model to estimate the ICU census in Daegu from the reported hospital data.

Findings

Multivariate regression analysis revealed male sex, old age, and residing in Daegu city as significant risk factors for ICU admission. The number of patients requiring ICU admission exceeded the bed capacity across all Daegu hospitals before March 9, 2020, and therefore, critically ill patients were transferred to nearby hospitals outside Daegu. This finding was consistent with our prediction that the ICU census in Daegu would peak on March 16, 2020, at 160 through mitigation efforts, without which it would have reached 300 by late March 2020.

Conclusion

Older age and male sex were risk factors for ICU admission. In addition, the geographic location of the hospital seems to contribute to the severity of the COVID-19 patients admitted to the ICU and to the ICU capacity.

Keywords:

• COVID-19 pandemic
• ICU admission
• Korea
• risk factors

Acknowledgments

The authors appreciate healthcare professionals dedicated to treating COVID-19 patients in Korea, and the Ministry of Health and Welfare and the Health Insurance Review & Assessment Service of Korea for sharing invaluable national health insurance claims data in a prompt manner.

Abbreviations

COVID-19, coronavirus disease; CFR, case fatality rate; NHIS, National Health Insurance System; HIRA, Health Insurance Review & Assessment Service; DM: diabetes mellitus; COPD, chronic obstructive pulmonary disease; ICD-10, International Classification of Diseases, 10th Revision; CT, computed tomography; aOR, adjusted odds ratio; 95% CI, 95% confidence interval.

Data Sharing Statement

The datasets used during the current study are available from the corresponding author on a reasonable request.

Ethics Approval and Consent to Participate

This study was approved by the Kyung Hee University Institute Research Board (KHSIRB-20-164). Informed consent was not required because this study used deidentified, open (publicly available) data.

Author Contributions

All authors made a significant contribution to the work. I-H Oh and SH Lee took part in the conception, study design and drafting. J. -Y Seon took part in the acquisition and analysis of data. H. -Y Kim, N. Thakkar and  P. Selvaraj performed model analysis and provision. A. Bershteyn, H. -Y Kim, J. -S Park, J. -H Park, N. Thakkar,  P. Selvaraj, S. -Y Park, S. -I Nam and W. -H Jeon carried out critical revision. All authors gave final approval of the version submitted have agreed on the journal to which the article has been submitted, and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no competing interests.

Additional information

Funding

This study was supported by a grant from the Korean Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (No. HI18C0446). The funding body had no role in the design of the study and collection, analysis, and interpretation of data and in writing of the manuscript.