Evaluating Frailty Screening Tools for Predicting Extended Length of Stay, 30-Day Readmission, and Complications for Patients Undergoing Anterior Cervical Discectomy and Fusion (ACDF)

Introduction: To compare the predictive accuracy of the Risk Analysis Index (RAI) and the Modified 5-item Frailty Index (mFI-5), along with patient age, in predicting extended length of stay (LOS), 30-day readmission, and 30-day complications among Anterior cervical discectomy and fusion (ACDF) spine surgery patients.

Methods: A retrospective cohort study was performed using the 2016-2021 ACS NSQIP database. Adults receiving elective ACDF spine surgery were identified using CPT codes. Using receiver operating characteristic (ROC) and multivariable analyses, we compared the discriminative thresholds and independent associations of RAI, mFI-5, and greater patient age with extended LOS, 30-day readmission, and 30-day complications.

Results: In our study of 64,055 patients undergoing ACDF spine surgery, the RAI categorized 96.1% as Robust, 3.2% as Normal, 0.6% as Frail, and 0.1% as Very Frail. Multivariate analyses indicated the RAI and mFI-5 as significant predictors of extended LOS [RAI Normal: aOR 4.14, p< 0.001; RAI Frail: aOR 4.74, p< 0.001; RAI Very Frail: aOR 13.75, p< 0.001; mFI-5 Frail: aOR 1.31, p< 0.001; mFI-5 Very Frail: aOR 2.19, p< 0.001]. The RAI significantly predicted 30-day readmission risk across all categories [Normal: aOR 1.70, p< 0.001; Frail: aOR 2.66, p< 0.001; Very Frail: aOR 3.42, p=0.001], as did the mFI-5 [Normal: aOR 1.23, p=0.001; Frail: aOR 1.65, p< 0.001; Very Frail: aOR 1.64, p< 0.001]. For 30-day complication risk, the mFI-5 was a significant predictor only in the Very Frail category (aOR 1.60, p< 0.001), while the RAI did not maintain significance in the multivariate model for any category.

Conclusion : Our analysis highlights the role of the RAI and mFI-5 in predicting postoperative outcomes for ACDF patients. The RAI effectively forecasts extended hospital stays and 30-day readmission risks across all patient frailty levels, while the mFI-5 specifically predicts 30-day complication risks in Very Frail patients. Notably, the RAI outperforms the mFI-5 in predicting extended length of stays and complication risks, highlighting its utility in preoperative assessments.