International Journal of Nursing Studies Volume 134, October 2022, 104311 Nurse staffing levels and patient outcomes: A systematic review of longitudinal studies

This systematic review examines the critical link between registered nurse staffing levels and patient safety by focusing specifically on longitudinal data, which tracks changes over time to better establish cause and effect. By analyzing twenty-seven studies across various hospital settings, the researchers aimed to move beyond simple correlations to confirm that higher staffing concentrations directly contribute to lower patient mortality rates. Although inconsistent reporting methods and a high risk of bias in some studies made direct comparisons difficult, the evidence generally suggests that well-staffed nursing teams lead to significantly better clinical outcomes. Ultimately, the paper concludes that maintaining robust numbers of registered nurses is a plausible causal factor in preventing patient deaths, underscoring the necessity for standardized staffing measures in future healthcare research.