Frailty Predicts 30-day mortality following major complications in neurosurgery patients: The risk analysis index has superior discrimination compared to modified frailty index-5 and increasing patient age

Background: Postoperative complications after cranial or spine surgery are prevalent, and frailty can be a key contributing patient factor. Therefore, we evaluated frailty's impact on 30-day mortality. We compared the discrimination for risk analysis index (RAI), modified frailty index-5 (mFI-5) and increasing patient age for predicting 30-day mortality. Methods: Patients with major complications following neurosurgery procedures between 2012- 2020 in the ACSNSQIP database were included. We employed receiver operating characteristic (ROC) curve and examined discrimination thresholds for RAI, mFI-5, and increasing patient age for 30-day mortality. Independent relationships were examined using multivariable analysis. Results: There were 19,096 patients included in the study and in the ROC analysis for 30-day mortality, RAI showed superior discriminant validity threshold C-statistic 0.655 (95% CI: 0.644-0.666), compared to mFI-5 Cstatistic 0.570 (95% CI 0.559-0.581), and increasing patient age C-statistic 0.607 (95% CI 0.595-0.619). When the patient population was divided into subsets based on the procedures type (spinal, cranial or other), spine procedures had the highest discriminant validity threshold for RAI (Cstatistic 0.717). Furthermore, there was a frailty risk tier dose response relationship with 30-day mortalityy (p<0.001). Conclusion: When a major complication arises after neurosurgical procedures, frail patients have a higher likelihood of dying within 30 days than their non-frail counterparts. The RAI demonstrated a higher discriminant validity threshold than mFI-5 and increasing patient age, making it a more clinically relevant tool for identifying and stratifying patients by frailty risk tiers. These findings highlight the importance of initiatives geared toward optimizing frail patients, to mitigate long-term disability.