Effects of registered nurse staffing on quality of care and resident outcomes in nursing homes

•The number of RNs is significantly related to patient mortality and quality of care.•RNs are crucial for health management and ensuring quality of care in nursing homes.•The overall evaluation of quality of care increased as the number of RNs increased. Few studies focus on Registered Nurse (RN) staffing and resident health outcomes in Korean nursing homes. This study aimed to investigate the effects of RN staffing on quality of care and resident outcomes in South Korean nursing homes. The study was a secondary data analysis of 5679 participants from the National Health Insurance Service. A mixed-effect linear model and multinomial logistic regression model assessed resident outcomes and quality of care, respectively. The number of RNs significantly affected patient mortality. The overall evaluation rating for quality of care in nursing homes increased as the number of RNs increased. Level of RN staffing in nursing homes influenced health management and quality of care for residents. A variety of efforts are needed to strengthen the workforce of RNs in nursing homes, including enacting a law for safe RN staffing and converting the evaluation of nursing home quality into health outcomes.