Korean NICU bloodstream infection rates fell, but hospital comparisons remain fragile

A five-year nationwide surveillance cohort covering 2.18 million NICU patient-days found lower BSI and CLABSI rates in Korea, yet persistent between-hospital variation and missing patient-level acuity data limit benchmarking and causal claims.

Korea’s national NICU surveillance curve moved in the right direction: pooled mean bloodstream infection (BSI) and central line–associated BSI (CLABSI) rates were lower in 2023–2024 than in 2019–2020. But this is a hospital surveillance signal, not patient-level proof that prevention programs caused fewer infections or improved survival. Persistent between-hospital variation and incomplete acuity adjustment make simple league-table conclusions especially fragile.

Despite overall improvement, substantial interhospital variability in both BSI and CLABSI rates persisted.

What the surveillance captured

This nationwide cohort analyzed the Korean National Healthcare-Associated Infections Surveillance System NICU module from July 2019 through June 2024. Infection-control practitioners prospectively submitted monthly exposure denominators and episode-level infection data under modified CDC definitions. All neonates admitted to participating eligible NICUs entered surveillance. Each year included 74 to 82 NICUs and 24,607 to 30,260 admissions; across five years, the database contained 2,178,107 patient-days and 585,582 central-line-days. Five grade-5 nurse-staffing hospital-years from three hospitals were excluded from 392 hospital-year observations because that category was too sparse for stable trend estimates.