Comparison of the performance metrics of two frailty scales in spinal surgery: a systematic review and meta-analysis.

Abstract

The United States is experiencing a significant demographic shift characterized by an increasingly aging population, or "silver tsunami." These demographic changes have profound implications for spine surgery outcomes, as spinal surgery is one of the most frequent procedures performed annually by neurosurgeons and orthopedic spine surgeons. In current literature, two frailty indices, the Modified Frailty Index (mFI-5 or mFI-11) and the Risk Analysis Index (RAI), are the indices predominantly utilized to risk assess patients prior to surgical treatment. Utilizing a systematic search yielded ten studies. This study employs the area under the curve (AUC) from receiver operating characteristic (ROC) curves to develop a linear regression model aimed at evaluating the predictive performance of these indices for specific outcomes. This investigation focuses on the performance of the mFI and RAI in predicting three key postoperative outcomes in spine surgery patients: 30-day mortality, Clavien-Dindo IV complications, and non-home discharge (NHD). The results indicate that the RAI demonstrates superior predictive accuracy compared to the mFI for 30-day mortality (RAI AUC 0.82 [0.78-0.85] vs. mFI AUC 0.66 [0.62-0.70]) and Clavien-Dindo III-IV complications (RAI AUC 0.69 [0.66-0.72] vs. mFI AUC 0.63 [0.62-0.63]). However, no significant difference was observed in the ability to predict NHD (RAI AUC 0.81 [0.63, 0.91] vs. mFI AUC 0.71 [0.64, 0.77]). These findings suggest that the Risk Analysis Index is a more reliable predictor of 30-day mortality and Major complications (Clavien-Dindo III-IV) in patients undergoing spine surgery.