Prognostic value of coagulation tests for in-hospital mortality of patients with traumatic brain injury

Abstract

Objective To evaluate the prognostic value of coagulation tests for in-hospital mortality of patients with traumatic brain injury (TBI). Methods We retrospectively analyzed the data of TBI patients who were admitted to Neurosurgery Department of Huashan Hospital, Fudan University, from December 2004 to June 2015. Two models were developed based on the admission characteristics. Model A included predictors such as age, Glasgow Coma Scale (GCS) score, pupil reactivity, type of injury, hemoglobin and glucose levels. Model B included the predictors in model A as well as coagulation test results. Performance of the models was assessed according to discrimination by means of the c statistic (equivalent to the area under the receiver operator characteristic curve) and calibration using the Hosmer-Lemeshow (H-L) goodness-of-fit test. Results A total of 2, 319 patients were enrolled into this study. Among them, 432 (18.63%) patients developed coagulopathy after TBI. The prevalence of acute traumatic coagulopathy was associated with the severity of brain injury. The percentage of platelet count 1.25, prothrombin time (PT)>14 sec, activated partial thromboplastin time (APTT)>36 sec, D-dimer>5 mg/L and fibrinogen (FIB) 1.25 and APTT>36 sec exhibited strong prognostic values in model B (P<0.05). Discrimination and calibration were good for the development group in both prediction models. However, the external validation test showed that calibration was better in model B than in model A for patients from the validation population (Hosmer-Lemeshow test, P=0.152 vs. P=0.046, respectively). Conclusions The coagulation function could serve as independent prognostic factor for in-hospital mortality of patients with traumatic brain injury. Incorporating the coagulation tests might improve the predictive power in relevant model. Key words: Craniocerebral trauma; Prothrombin; Hospital mortality; Prediction model