Nationwide pediatric injury surveillance across two successive system disruptions in South Korea, 2016–2024

Abstract Background Long-term trends in emergency department (ED)-based pediatric injury surveillance during and after the COVID-19 pandemic remain poorly characterized, particularly in settings that experienced additional system-level disruption. In February 2024, South Korea experienced a second healthcare-system disruption following the mass resignation of trainee physicians from teaching hospitals after a government decision to expand medical school admissions. Methods We analyzed National Emergency Department Information System data for children aged under 10 years with injury diagnoses (S00–T79) or external cause codes (V01–Y98), January 2016 to December 2024 (108 months). Monthly ED-recorded injury visit rates were calculated using resident-registration pediatric population denominators. Interrupted time-series analysis used two prespecified breakpoints (COVID-19 onset, March 2020; mass resignation of trainee physicians, February 2024). Recovery Indices compared 2023 with 2018–2019, stratified by resource intensity (KTAS 1–2, ICU, death, or transfer-in) and facility type. Results Among 2,783,933 pediatric injury-related ED visits over 9 years, population-adjusted injury contact burden remained incompletely recovered by 2023 (Recovery Index 78.7% after adjusting for a 20.3% pediatric population decline; raw Recovery Index 62.7%), with the transfer-excluded resource-intensity group recovering more completely than the non-resource group (Recovery Index 76.2% vs. 62.3%), suggesting a post-COVID shift in the recorded ED case mix. Regional emergency centers recovered most by 2023 (71.5%) but showed the largest decline at the February 2024 breakpoint (β=−88.7 per 100,000), while non-teaching facilities showed no detectable change (β=+2.4). The level change at the February 2024 breakpoint was − 157.9 per 100,000 (95% CI − 223.7 to − 92.0), against − 183.3 (95% CI − 220.2 to − 146.5) at COVID-19 onset. Conclusions ED-recorded pediatric injury contacts in South Korea remained below pre-pandemic levels, while the recorded case mix showed a relative shift toward more resource-intensive presentations. The 2024 trainee-physician workforce disruption was associated with a second, facility-selective decline that was largest in regional emergency centers and not detectable in other emergency facilities; with 11 months of follow-up these estimates are preliminary. These findings show that pediatric injury surveillance during healthcare-system disruption should not rely on visit counts alone; case mix and facility-tier distribution are needed to interpret ED-recorded injury trends.