Frailty and postoperative risk in geriatric neurosurgery: a prospective cohort study using multidimensional assessment.

Frailty is increasingly recognized as a major determinant of surgical risk in older adults; however, its prognostic significance in the context of elective neurosurgery remains unclear. This study investigated the prevalence of frailty, the concordance between three validated frailty instruments, and their association with postoperative complications. A prospective cohort study was conducted at a tertiary neurosurgical center from November 2021 to November 2024. Patients aged ≥ 65 years undergoing elective cranial or spinal surgery were included. Preoperative frailty was assessed using the Clinical Frailty Scale (CFS), the Comprehensive Geriatric Assessment Frailty Index (CGA-FI), and the Fried's Frailty Phenotype (FFP) criteria. Postoperative complications-including infectious, cardiovascular, neurological, haemorrhagic events, delirium, and in-hospital death-were systematically recorded. Associations with frailty were examined using multivariable logistic regression adjusted for covariates. Among 181 patients (mean age, 74.1 [SD] 6.1 years), frailty prevalence ranged from 23.8% (CGA-FI) to 44.2% (FFP). Agreement between instruments was variable, with substantial concordance between CFS and CGA-FI (κ = 0.65) and only moderate concordance with FFP. Postoperative complications occurred in 47 (25.9%) patients. Frailty defined by CFS (adjusted odds ratio [aOR], 2.73; 95% CI, 1.05-7.42) and CGA-FI (aOR, 3.78; 95% CI, 1.34-11.1) was independently associated with increased risk of complications. In conclusion, frailty as assessed by the CFS and CGA-FI, is a strong determinant of postoperative risk in older adults undergoing elective neurosurgery. Incorporating frailty assessment into routine neurosurgical pathways may improve perioperative risk stratification and guide clinical decision-making.