Objective:

To compare the predictive performance of the modified Frailty Index-5 (mFI-5) and the Risk Analysis Index (RAI) in octogenarians undergoing elective anterior cervical procedures. 

Background:

Anterior cervical spine procedures in octogenarians carry high perioperative risk. Frailty is a known predictor of surgical outcomes, yet the comparative performance of different frailty indices in this population is unclear. 

Design/Methods:

We analyzed ACS-NSQIP data (2015–2021) for patients aged 80–89 years undergoing anterior cervical procedures. The primary outcome was 30-day mortality; secondary outcomes included major complications, readmission, reoperation, and non-home discharge. Frailty was assessed with mFI-5 and RAI. Multivariable logistic regression and AUROC analysis with DeLong test and bootstrap validation evaluated model performance. 

Results:

Among 870 patients, 19.5% were frail by RAI and 14.5% by mFI-5. RAI demonstrated superior discrimination for 30-day mortality (AUROC 0.830 vs 0.514, p<0.001; adjusted OR 1.31, 95% CI 1.14–1.50). RAI also outperformed mFI-5 for non-home discharge (AUROC 0.674 vs 0.528, p<0.001), readmission (0.607 vs 0.504, p=0.022), and extended length of stay (0.627 vs 0.540, p=0.003). Bootstrap validation confirmed stability of results. 

Conclusions:

RAI demonstrated superior discrimination compared to mFI-5 for predicting mortality and postoperative outcomes in octogenarians undergoing anterior cervical procedures. RAI may provide more accurate risk stratification, supporting improved surgical planning, perioperative management, and patient counseling in this high-risk population.