Nurse staffing level and overtime associated with patient safety, quality of care, and care left undone in hospitals: A cross-sectional study

Objective: The purpose of this study was to explore the association of nurse staffing and overtime with nurse-perceived patient safety, nurse-perceived quality of care, and care left undone. Design: A cross-sectional survey. Setting and participants: A total of 65 hospitals were selected from all of the acute hospitals (n = 295) with 100 or more beds in South Korea by using a stratified random sampling method based on region and number of beds, and 60 hospitals participated in the study. All RNs working on the date of data collection in units randomly selected from the list of units in each hospital were invited to participate. The analyses in this study included only bedside RNs (n = 3037) and hospitals (n = 51) with responses from at least 10 bedside RNs. Methods: We collected data on nurse staffing level, overtime, nurse-perceived patient safety, nurse-perceived quality of care, nurse-reported care left undone, and nurse characteristics through a nurse survey. Facility data from the Health Insurance Review Agency (HIRA) were used to collect hospital characteristics. Multilevel logistic regression models considering that nurses are clustered in hospitals were used to analyze the effects of hospital nurse staffing and overtime on patient safety, quality of care, and care left undone. Results: A higher number of patients per RN was significantly associated with higher odds of reporting poor/failing patient safety (OR = 1.02, 95% CI = 1.004-1.03) and poor/fair quality of care (OR = 1.02, 95% CI = 1.01-1.04), and of having care left undone due to lack of time (OR = 1.03, 95% CI = 1.01-1.05). Compared with RNs who did not work overtime, RNs working overtime reported an 88% increase in failing or poor patient safety (OR = 1.88, 95% CI = 1.40-2.52), a 45% increase in fair or poor quality of nursing care (OR = 1.45, 95% CI = 1.17-1.80), and an 86% increase in care left undone (OR = 1.86, 95% CI = 1.48-2.35). Conclusions: Our findings suggest that ensuring appropriate nurse staffing and working hours is important to improve the quality and safety of care and to reduce care left undone in hospitals.