Related Experiment Video
Updated: May 21, 2026
Three-dimensional Navigation-guided, Prone, Single-position, Lateral Lumbar Interbody Fusion Technique
Published on: July 15, 2021
Risk Analysis Index Outperforms Modified Frailty Index-5 for Predicting Adverse Outcomes Following Anterior Lumbar
Cameron J Sabet1, Bhav Jain2, Jad Lawand3
1Georgetown University Medical Center, Washington, DC.
Study Design:
Retrospective cohort study.
Objective:
To compare the predictive performance of the modified Frailty Index-5 (mFI-5) and the Risk Analysis Index (RAI) for postoperative outcomes following anterior lumbar interbody fusion (ALIF) in active smokers.
Summary Of Background Data:
Anterior lumbar interbody fusion (ALIF) accounts for a substantial proportion of the over 350,000 interbody spinal fusions performed annually in the United States. Frailty assessment tools may improve risk stratification, particularly in vulnerable populations such as active smokers. The comparative performance of mFI-5 and RAI in this context remains unknown.
Methods:
We analyzed ACS-NSQIP data (2015-2021) for patients aged 50 years or older undergoing elective ALIF who were active smokers. Frailty was assessed using mFI-5 (functional dependence, diabetes, COPD, CHF, and hypertension) and RAI (age, sex, comorbidity burden, and functional status). Multivariable logistic regression was used to evaluate associations with outcomes. Discrimination was assessed using AUROC with DeLong tests, and model performance was validated with 100 bootstrap resamples.
Results:
Among 2806 active smokers, 50.3% were classified as frail by mFI-5 and 22.9% by RAI. Nonhome discharge occurred in 10.2% of patients. The RAI demonstrated higher discrimination compared with mFI-5 for nonhome discharge (AUROC=0.732 vs. 0.639, P<0.001), extended length of stay (0.633 vs. 0.568, P<0.001), and minor complications (0.698 vs. 0.520, P=0.013). Performance was similar for mortality, readmission, and reoperation.
Conclusions:
The RAI demonstrated better discrimination than the mFI-5 in predicting nonhome discharge and select postoperative outcomes following ALIF in active smokers. These findings support the RAI as a frailty measure with better discriminative performance for risk stratification in this high-risk population, though confounding by smoking-related impairment cannot be excluded.
