Prospective validation of a proposal for diagnosis and management of patients attending the emergency department for mild head injury

Background: In mild head injury, predictors to select patients for computed tomography (CT) and/or to plan proper management are needed. The strength of evidence of published recommendations is insufficient for current use. We assessed the diagnostic accuracy and the clinical validity of the proposal of the Neurotraumatology Committee of the World Federation of Neurosurgical Societies on mild head injury from an emergency department perspective. Methods: In a three year period, 5578 adolescent and adult subjects were prospectively recruited and managed according to the proposed protocol. Outcome measures were: ( a) any post-traumatic lesion; (b) need for neurosurgical intervention; ( c) unfavourable outcome ( death, permanent vegetative state or severe disability) after six months. The predictive value of a model based on five variables ( Glasgow coma score, clinical findings, risk factors, neurological deficits, and skull fracture) was tested by logistic regression analysis. Findings: At first CT evaluation 327 patients (5.9%) had intracranial post-traumatic lesions. In 16 cases (0.3%) previously undiagnosed lesions were detected after re-evaluation within seven days. Neurosurgical intervention was needed in 71 patients (1.3%) and an unfavourable outcome occurred in 39 cases (0.7%). The area under the ROC curve of the variables in predicting post-traumatic lesions was 0.906 (0.009) ( sensitivity 70.0%, specificity 94.1% at best cut off), neurosurgical intervention was 0.926 (0.016) ( sensitivity 81.7%, specificity 94.1%), and unfavourable outcome was 0.953 (0.014) ( sensitivity 88.1%, specificity 95.1%). Interpretation: The variables prove highly accurate in the prediction of clinically meaningful outcomes, when applied to a consecutive set of patients with mild head injury in the clinical setting of a 1st level emergency department.