This cost-effectiveness analysis examined a variety of patient-to-nurse ratios in general medical and surgical settings. Investigators determined that an 8:1 ratio created the least expense but was also associated with the highest mortality rates. While decreasing the ratio incrementally to 4:1 improved mortality rates, it became more costly and progressively less cost-effective, but not outside of acceptable ranges. The authors conclude that defined nurse staffing ratios provide an opportunity for a cost-effective patient safety intervention comparable to other interventions of similar scope.