Delayed at the Door: Impact of Pandemic Response Policies on Emergency and Critical Care in Korea: An Interrupted Time-Series Analysis

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic strained emergency and critical care systems globally, limiting access. Although Korea has been recognized for effective containment, the impact of the pandemic and its response policies on critical care accessibility remains unclear. METHODS: We conducted a nationwide interrupted time-series analysis of patients admitted from emergency department (ED) to intensive care unit (ICU) in Korea (January 2015-December 2023). The study period was divided into pre-pandemic, pandemic phase 1 (January 2020-March 2022; strict infection control with segregated COVID-19 care), and pandemic phase 2 (April 2022 onwards; reintegration of COVID-19 care). Negative binomial regression was used for ED-to-ICU admissions, and seasonal autoregressive integrated moving average models for the proportion of ED length of stay (EDLOS) ≥ 6 hours and in-hospital mortality. RESULTS: At pandemic onset, ED-to-ICU admissions declined immediately by 6.66% (95% confidence interval [CI], -9.25 to -3.98) and continued to fall by 0.54% per month (95% CI, -0.69 to -0.39) throughout phase I. Despite this, in-hospital mortality rose by 0.08% monthly (95% CI, 0.02 to 0.14), while EDLOS ≥ 6 hours increased by 0.35% per month (95% CI, 0.24 to 0.47). In phase 2, ED-to-ICU admissions rebounded with a 1.22% monthly increase (95% CI, 0.96 to 1.48), while mortality (-0.10% monthly, 95% CI, -0.20 to -0.01) and EDLOS ≥ 6 hours (-0.98% monthly, 95% CI, -1.18 to -0.77) declined. CONCLUSION: During the COVID-19 pandemic, marked changes in Korea's ED-to-ICU admission and in-hospital mortality were observed, reflecting the consequence of pandemic response policies. While infection control was essential, strict segregated COVID-19 care system likely limited ICU access for non-COVID patients, contributing to reduced admissions and increased mortality. These findings underscore the need for policies that balance rigorous infection control with flexible ICU management and effective patient flow strategies during public health emergencies.