Risk Analysis Index as a Predictor of Mortality and Failure to Rescue in Patients Undergoing Distal Femur Fracture Fixation.

Purpose: This study sought to evaluate the use of frailty, compared to age alone and American Society of Anesthesiologists (ASA) score, for prediction of mortality and failure to rescue (FTR) in patients undergoing surgical fixation of distal femur fractures (DFFs). Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for patients who underwent surgical management of DFFs. Frailty was evaluated using the 5-Item Modified Frailty Index (mFI-5) and Risk Analysis Index (RAI). Outcomes included 30-day mortality and FTR (mortality following major complication). Multivariate regression and receiver operating characteristic curve (AUROC) analyses were performed to assess odds ratio (OR) and discriminatory accuracy (quantified by C-statistic), respectively. Results: There were 2638 patients (median age 73 years) undergoing DFF fixation included in this study. Of these, 90 (3.4%) patients experienced mortality, while FTR occurred in 51 (1.9%) patients. Increasing frailty, as rated by the mFI-5 and RAI, was significantly associated with higher odds of 30-day mortality and FTR in patients undergoing surgical fixation of DFF. Additionally, RAI showed superior discriminatory accuracy for 30-day mortality and FTR compared to mFI-5, age, and ASA. Conclusions: The RAI demonstrates superior predictive value and discriminatory accuracy for postoperative mortality. Given these findings, frailty as measured by the RAI may be a useful bedside screening tool to identify patients at risk for adverse outcomes. In doing so, patients can be optimized preoperatively to improve clinical care.