Emergency-Care Utilisation During Two Healthcare Crises in South Korea: A Single-Centre Comparison of Calendar-Aligned 32-Week Windows

Background/Objectives: Emergency department (ED) attendance may change differently from subsequent hospital utilisation during healthcare disruptions. We compared two historical crisis episodes within one Korean regional emergency medical centre.

Methods

Four calendar-aligned 224-day windows before and after the onset of COVID-19 and the 2024 workforce disruption were analysed using episode-by-phase interactions. Modified Poisson models used patient-and-day two-way clustered variance. Less-conditioned and initial-acuity-conditioned models were compared. Daily counts used calendar-lag autocorrelation-consistent variance. Source-data audits, full-period segmented analyses and alternative-baseline sensitivities were added.