Abstract
BACKGROUND: A good nursing work environment is a key determinant of patient safety. In 2018, the Korean government introduced the Nurse Working Conditions Improvement Policy (NWCIP), accompanied by a revision of the nurse staffing grade calculation method. Under this policy, hospitals with revenue growth due to upward adjustments in nurse staffing grade were recommended to allocate revenue growth for improving nurses' working conditions. OBJECTIVE: To evaluate whether funding under the NWCIP, aimed at improving nurses' working conditions, is associated with changes in patient outcomes. METHODS: A quasiexperimental study was conducted using National Health Insurance claims data from 198,318 adult inpatients across 99 general hospitals. After confirming the parallel trends assumption, a difference-in-differences approach was used to evaluate the policy's effect. Patient outcomes were compared between the first quarters of 2018 (baseline) and 2019 (postimplementation). Hospitals were categorized into an intervention group (those that received nurses' working conditions improvement fund) and a comparison group (those that did not). Outcomes included in-hospital mortality, 7-day readmission, and length of stay. Among the 99 hospitals, 60 were assigned to the intervention group and 39 to the comparison group. RESULTS: According to difference-in-differences analysis, the intervention group showed a 19% increase in 7-day readmission (adjusted odds ratio = 1.19; 95% confidence interval: 1.09-1.29; p < 0.001) and a 5% decrease in length of stay (adjusted incidence rate ratio = 0.95; 95% confidence interval: 0.92-0.97; p < 0.001), with no significant change in in-hospital mortality. CONCLUSIONS: General hospitals subject to the NWCIP did not show improved patient outcomes: They had a higher risk of readmission despite a shorter length of stay. IMPLICATIONS FOR NURSING MANAGEMENT: The use of revenue growth to improve nurses' working conditions should be mandated rather than recommended, prioritizing high-impact staffing investments, such as hiring additional nurses, most directly linked to patient outcomes.