ABSTRACT THE IMPACT OF NURSING SKILL MIX ON THE OUTCOMES OF HOSPITALIZED ADULT SURGICAL PATIENTS Danielle Altares Sarik Ann Kutney-Lee Rates of harm to surgical patients remain largely unchanged despite decades of initiatives to address safety concerns, while wide variations in mortality and failure to rescue (FTR) persist between hospitals. Despite the critical role that registered nurses (RNs) play in providing care to hospitalized patients, there has been limited exploration of the relationship between nursing skill mix and surgical patient outcomes. The purpose of this study was to examine the association between nursing skill mix and adult surgical patient 30-day mortality and FTR. This retrospective, cross-sectional, secondary data analysis utilized three datasets to study surgical patient outcomes in four states (California, Florida, New Jersey, Pennsylvania): the 2006-2007 Multi-State Nursing Care and Patient Safety Survey, the 2006-2007 American Hospital Association Annual Survey, and hospital discharge abstracts for patients age 18-85 years who underwent general, orthopedic, or vascular surgical procedures in non-federal acute care hospitals in 2006-2007. A total of 1,267, 516 surgical patients, 29,391 nurses, and 665 hospitals comprised the final sample. Logistic regression models were used to assess the association of nursing skill mix, defined as the proportion of RNs to all nursing staff (RNs, licensed practical and vocational nurses (LPN/LVNs), and unlicensed assistive personnel (UAPs)) on 30-day mortality and FTR. After analysis, each 10% increase in RN skill mix was associated with a 7% decrease in the odds of 30-day mortality (P<0.001) and FTR (P<0.01) in the surgical patient population. Additionally, each 10% increase in the proportion of LPN/LVNs was associated with a 6% increase in the odds of both 30-day mortality (P<0.05) and FTR (P<0.05), while every 10% increase in UAP proportion was associated with a 6% increase in the odds of 30-day mortality (P<0.01) and a 5% increase in the odds of FTR (P<0.05). As healthcare reform continues to place pressure on hospital administrators to increase quality and decrease costs, maintaining a nursing skill mix with a high proportion of RNs may be one strategy to improve surgical patient mortality and FTR.