Resident Physician University of New Mexico Albuquerque, NM, US
Introduction: The Risk Analysis Index (RAI) is a quantitatively robust frailty index recently recalibrated and validated for calculation in administrative databases and the clinical setting. The aim of this study was to evaluate the utility of the baseline frailty (measured by RAI) for prediction of postoperative outcomes after surgery for malignant spinal tumors.
Methods: he metastatic spinal tumor patient population was queried from the NSQIP (2011-2020) using a combination of Current Procedural Terminology (CPT) codes and International Classification for Disease (ICD), 9th and 10th Revision, Clinical Modification codes. The association between preoperative RAI score and postoperative outcomes was assessed using proportional trend tests and area under the receiver operating characteristic (ROC) curve analysis.
Results: Among 2235 patients undergoing surgery for malignant spinal tumors, 507 were RAI 0-20, 266 were RAI 21-30, 1222 were RAI 31-40, and 240 were RAI 41+. In terms of outcomes, there were 181 major complication occurrences (8.1%), 126 CD IV occurrences (5.6%), 937 NHDs (42%), 571 eLOS (26%), and 136 mortalities within 30-days (6.1%). Increasing RAI score (in stepwise 5-point bins) was statistically significantly associated with increasing occurrence rate of major complication, CD IV, eLOS, NHD, and 30-day mortality (all P< 0.05). The rate of primary outcome, 30-day mortality, was 6.1% (N=136) and was significantly associated with increasing frailty (by RAI). RAI demonstrated robust discriminatory accuracy for prediction of primary endpoint in ROC analysis (C-statistic: 0.717, 95% CI: 0.697-0.735). On pairwise ROC comparison, RAI score had statistically significant better discriminatory accuracy compared to mFI-5 and chronological age (both P< 0.001, DeLong test).
Conclusion : This was the first study to link baseline frailty (quantified by RAI score) to outcomes after surgery for malignant spinal tumors. The burden of frailty-associated risk is particularly elevated in this patient population and necessitates meticulous preoperative risk stratification and patient counseling.
