Predictive Value of Geriatric Nutritional Risk Index and Risk Analysis Index for Post-operative Outcomes in Spine...

Area of Science:

• Orthopedic Surgery
• Geriatric Medicine
• Surgical Outcomes Research

Background:

• Frailty and nutritional status significantly impact spine surgery outcomes.
• Existing risk assessment tools may not fully capture complex patient vulnerabilities.

Purpose of the Study:

• To evaluate the predictive utility of a combined Risk Analysis Index (RAI) and Geriatric Nutritional Risk Index (GNRI) model.
• To introduce and validate the Compound Geriatric Assessment Risk Prediction (CGARP) score for spine surgery patients.

Main Methods:

• Retrospective cohort study using the National Surgical Quality Improvement Program (NSQIP) database (2015-2020).
• Multivariable logistic regression developed the CGARP score, integrating RAI, GNRI, American Society of Anesthesiologists (ASA) classification, and Preoperative Acute Severe Condition (PACS).
• Model performance assessed using area under the receiver operating characteristic curve (AUROC).

Main Results:

• Increasing frailty and malnutrition were independently associated with worse postoperative outcomes in 360,133 patients.
• The CGARP model demonstrated superior predictive performance across multiple outcomes, including mortality (AUROC=0.882) and non-home discharge (AUROC=0.762).
• Random Forest machine learning achieved the highest predictive accuracy (AUC=0.9553).

Conclusions:

• The CGARP compound score offers superior predictive performance for adverse outcomes in spine surgery compared to individual predictors.
• This validated model provides clinically actionable risk stratification, aiding in preoperative decision-making and patient management.
• Frailty and nutritional risk are critical, independent predictors of surgical outcomes.