Abstract: Objective To investigate the predictive value of the fibrinogen-to-albumin ratio (FAR) for deep vein thrombosis (DVT) in patients following chronic subdural hematoma (CSDH) evacuation.Methods We conducted a retrospective cohort study of CSDH patients who underwent surgical evacuation at Shiyan Taihe Hospital (June 2015-June 2025).DVT was diagnosed via Doppler ultrasonography during hospitalization.Baseline characteristics including serological parameters,imaging findings,medical history,and anesthesia techniques were collected upon admission.The association between FAR and DVT was assessed using multivariate Logistic regression and restricted cubic spline (RCS) analyses.We performed hierarchical regression to identify effect modifiers and constructed receiver operating characteristic (ROC) curves to evaluate FAR's predictive performance.Results Among 238 enrolled CSDH patients,29 (12.2%) developed postoperative DVT.Elevated FAR showed a significant positive association with DVT risk (adjusted OR 1.33,95%CI 1.18-1.49).After multivariable adjustment,the ROC analysis demonstrated good discrimination (AUC=0.85),with the highest FAR quartile showing significantly increased DVT risk (OR 7.05,95%CI 1.24-68.3) versus the lowest quartile.The RCS curve showed a linear relationship between FAR and DVT (P-value=0.035,P-Nonlinear=0.512),and the threshold effect analysis was used to determine that the predicted critical value of FAR was 12.6%.Conclusion In patients with chronic subdural hematoma,the FAR ratio is associated with the risk of DVT,and further study of the FAR ratio may be helpful for the prevention and treatment of DVT.

Key words: chronic subdural hematoma; deep vein thrombosis; fibrinogen-to-albumin ratio