BackgroundIn South Korea, various quality assessments have been introduced to improve the quality of care; thus, the overall quality level of medical institutions has improved. However, gaps still exist between medical institutions. AimThis study evaluated the impact of medical institutions’ quality management efforts on securing medical staff and healthcare-associated infections in intensive care units (ICUs). MethodsThis study used data from the second and third ICU quality assessments conducted by the Health Insurance Review and Assessment Service, which included 265 hospitals and 39,096 inpatients. The continuous quality improvement efforts of medical institutions were measured according to changes in their grade based on quality assessment results. We also measured healthcare-associated infection rates, including rates for ventilator-associated pneumonia and catheter-associated infections. The incidence rate ratio (IRR) was calculated using generalized estimating equation Poisson regression models that included hospital and patient characteristics. ResultsHealthcare-associated infections occurred in approximately 2% of patients with ventilators or catheters. Ventilator-associated pneumonia significantly increased in institutions with a decline in grade (IRR: 2.038, 95% CI: 1.426‒2.915). In institutions with an upgrade in grade, infections associated with the central venous catheter (IRR: 0.484; 95% CI: 0.330‒0.711) and urinary catheter (IRR: 0.587, 95% CI: 0.398‒0.866) decreased. ConclusionsAlthough quality assessment has been introduced in ICUs in South Korea, some gaps remain among medical institutions. Differences were observed in securing medical resources through the quality management efforts of medical institutions, and the infection rate was low in hospitals with high-quality management and high in hospitals with low-quality management.