To analyze the relevant risk factors of lower limb venous thrombosis (VET) secondary to acute traumatic brain injury (TBI) and establish a predictive model.

A retrospective study was conducted on 200 acute TBI patients who underwent Neurosurgery Department of Bethune Hospital, Shanxi Medical University January 2020 to September 2022. General information, imaging data, and test indicators of the patients were collected 24 h after admission. Based on the results of lower limb ultrasound examination during hospitalization, the patients were divided into VTE group (54 cases) and non VTE group (146 cases). The various indicators of the two groups of patients were compared, the independent risk factors for lower limb VET in TBI patients were analyzed, and the risk prediction model was established. The predictive value of the model was evaluated by drawing ROC curves.

There were statistically significant differences in age, white blood cell count, neutrophil count, platelet count, admission GCS≤8 score, and lower limb immobilization between VTE group and the non VTE group (P<0.05). The multivariate Logistic regression analysis showed that age, admission GCS≤8 score, and lower limb immobilization were independent risk factors for lower limb VET in patients with acute TBI (P<0.05). A column chart prediction model was constructed using risk factors. ROC curve analysis showed that the area under the curve for lower limb VET in TBI patients diagnosed with age, admission GCS≤8 score, and lower limb immobilization were 0.716 (95%CI: 0.642-0.791), 0.407 (95%CI: 0.341-0.500), and 0.596 (95%CI: 0.501-0.691), respectively. The AUC value of the model (represented by the combined variable PRE) was 0.770 (95%CI: 0.698-0.841), indicating that the model has a good predictive effect on lower limb VET in TBI patients.

Age, lower limb immobilization, and admission GCS≤8 score are independent risk factors for lower limb VET in acute TBI patients, and the constructed risk prediction model has certain predictive value.