Frailty Predicts Neurological Outcome in Chronic Subdural Hematoma: A Single-Center Prospective Cohort Study

Objectives: Frailty, reflecting reduced physiological reserve, has emerged as a predictor of postoperative outcomes in neurosurgery and may provide greater prognostic value than age. In chronic subdural hematoma (cSDH), prospective data remain scarce. This study investigates the association between preoperative frailty, assessed using the Clinical Frailty Scale (CFS), and postoperative recovery in cSDH patients. Methods: In this ongoing prospective single-center cohort study, 78 consecutive patients (≥60 years) with cSDH were enrolled between August 2022 and October 2024. After exclusion of four conservatively managed patients, 74 surgically treated patients were included in the analysis. Frailty was defined as Clinical Frailty Scale (CFS) ≥ 5. The primary outcome was the Glasgow Outcome Scale-Extended at 6 months (GOSE6). Secondary outcomes included GOSE at discharge (GOSE0) and three months (GOSE3), revision surgery, intensive care unit (ICU) admission, and mortality after six months. Results: Higher CFS scores significantly correlated with poorer outcome at 6 months (r = −0.68, padj = 0.011). In regression analysis, frailty (p < 0.001), age (padj = 0.014), and revision surgery (padj = 0.009) were significant predictors of outcome. Frailty was associated with a reduced likelihood of a good neurological outcome (OR = 0.02, 95% CI: [0.004, 0.085]). Frail patients had significantly poorer outcomes at all timepoints (all padj = 0.014) and none achieved a favorable outcome (GOSE ≥ 6). Six-month mortality was significantly higher in frail patients compared to non-frail patients (32% vs. 4%, padj = 0.048, relative risk RR = 3.29, 95% CI [1.67, 5.78]). Conclusions: Our interim results suggest that preoperative frailty, as measured by the CFS, is strongly associated with poorer neurological recovery and higher mortality following surgical treatment of cSDH. Frailty assessment may facilitate individualized treatment strategies and improve risk stratification beyond age or comorbidity burden.