Assessing the Independent and Cumulative Effects of Frailty, Malnutrition, and Anemia on Outcomes after Intracranial Tumor Resection in Older Adults

Purpose: To evaluate the independent and combined influence of frailty, anemia, and malnutrition on postoperative outcomes in elderly patients undergoing intracranial tumor resection. Methods: We analyzed ACS-NSQIP data (2011–2022) for patients ≥ 65 years undergoing craniotomy for tumor resection. Frailty was assessed using the revised Risk Analysis Index (RAI-rev), anemia was defined by preoperative hematocrit, and malnutrition was defined as Geriatric Nutritional Risk Index (GNRI) = < 98. Outcomes included extended length of stay (LOS), 30-day adverse events (AEs), nonroutine discharge (NRD), and 30-day mortality. Multivariable logistic regression and ROC analyses were performed. Results: Among 6,329 patients, 29.2% were frail alone, 10.9% frail + anemic, 17.0% frail + malnourished, 16.4% frail + anemic + malnourished, and 26.5% not frail. Frailty (aOR 1.09, 95% CI 1.07–1.12), anemia (aOR 1.26, 95% CI 1.04–1.52), and malnutrition (aOR 0.95, 95% CI 0.94–0.96) independently predicted extended LOS. Anemia (aOR 1.40, 95% CI 1.16–1.70) and malnutrition (aOR 0.98, 95% CI 0.97–0.99) were significantly associated with 30-day AEs. Malnutrition predicted NRD (aOR 0.98, 95% CI 0.97–0.99), and both frailty (aOR 1.06, 95% CI 1.03–1.09) and malnutrition (aOR 0.98, 95% CI 0.96–1.00) predicted 30-day mortality. The combined frailty + anemia + malnutrition model yielded the highest AUCs for all outcomes and significantly outperformed frailty alone for LOS (p < 0.001) and AEs (p = 0.008). Conclusion: Frailty, anemia, and malnutrition are independent predictors of poor postoperative outcomes in elderly patients undergoing intracranial tumor resection. Their combined use improves perioperative risk stratification for LOS and AEs, supporting integration of physiologic screening into neurosurgical workflows to advance value-based care.