Prognosis analysis and risk factors related to persistent unconscious patients after severe traumatic brain injury

Abstract

Objective To investigate the risk factors related to persistent unconsciousness in patients with severe traumatic brain injury (sTBI) by way of building a prognosis model. Methods The clinical data of 165 sTBI patients admitted from July 2011 to November 2013 were retrospectively analyzed. The eligible patients were randomly assigned to derivation cohort (n =115) and verification cohort (n =50) by treatment order. Inclusion criteria: (1) age >15 years; (2) definitive history of head injury; (3) traumatic brain injury confirmed by head computerized tomography or brain MRI; (4) initial Glasgow coma score (GCS) was less than 8; (5) patient' s light come or consciousness impairment gradually deteriorating to profound coma on the day of admission. The exclusion criteria were as follows: (1) only a brief loss of consciousness or coma after trauma (coma time <6 hours) ; (2) post-injury hysteria or dementia causes appearance like coma; (3) unconsciousness results of status epilepticus which was induced by emotion after injury. Univariate and multivariable logistic regression were employed to determine the independent predictors of persistent unconsciousness in the derivation cohort, and then prognosis model was established. The Hosmer-Lemeshow goodness-of-fit test and the area under the receiver operating characteristic curve were used to assess the capacity of model for discrimination and calibration. Results Logistic regression analysis was used to identify GCS score, neurological complications, diffuse axonal injury (DAI) , electrolytes disturbance as the most important predictors of persistent unconsciousness. The model was well calibrated in the derivation cohort (Hosmer-Lemeshow test, χ2 =4.380, P =0.496) . The model showed good discrimination (area under the receiver operating characteristic curve) in the derivation cohort (0.87; 95% CI: 0.798 -0.942) and in the versification cohort (0.90; 95%CI: 0.803 -0.997) . Conclusions The prognosis model could accurately predict the persistent unconsciousness lasting in sTBI patients despite its certain limitations, and therefore, it has significantly clinical and societal value. Key words: Traumatic brain injury; Coma; Risk factor; Prognosis; Model