A Comparison of Frailty Indices in Predicting Postoperative Outcomes After Endoscopic Sinus Surgery

OBJECTIVE: To compare the discriminatory performance of the Risk Analysis Index (RAI) and modified Frailty Index-5 (mFI-5) in predicting postoperative outcomes following endoscopic sinus surgery (ESS). STUDY DESIGN: Retrospective cohort study. METHODS: Adult ESS patients were identified from the ACS-NSQIP database (2005-2020). Frailty was quantified using the RAI and mFI-5. Multivariable logistic regression evaluated associations between frailty strata and postoperative outcomes, including Clavien-Dindo (CD) complications, extended length of stay (eLOS), non-home discharge (NHD), wound complications, and mortality. Model discrimination was assessed using receiver operating characteristic analysis with area under the curve (AUC) as the primary comparative metric. RESULTS: Among 1871 patients, increasing frailty was independently associated with adverse postoperative outcomes across both indices. However, discriminatory performance differed meaningfully. The RAI demonstrated superior discrimination for NHD (AUC 0.796 vs. 0.721), CD II complications (0.722 vs. 0.547), and mortality (0.742 vs. 0.684), and CD IV (0.737 vs. 0.656), with comparable performance for eLOS (0.647 vs. 0.636). Overall, the RAI more consistently separated patients at risk for recovery- and disposition-related endpoints. CONCLUSION: Frailty is a significant predictor of postoperative outcomes after ESS. While both indices identified elevated risk, the RAI demonstrated stronger and more consistent discrimination across clinically meaningful endpoints, particularly those reflecting postoperative recovery and resource utilization. Multidomain frailty assessment may therefore provide more informative risk stratification than comorbidity-based tools in elective rhinologic surgery.