Citation

Han J, King N, Neilson S, Gandhi M, Ng I. J. Neurotrauma 2014; 31(13): 1146-1152.

Affiliation

National Neuroscience Institute, Department of Neurosurgery, Singapore, Singapore ; julianhanxg@gmail.com.

Copyright

(Copyright © 2014, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2013.3003

PMID

24568201

Abstract

An accurate prognostic model is extremely important in severe traumatic brain injury (TBI) for both patient management and research. Clinical prediction models must be validated both internally and externally before they are considered widely applicable. Our aim is to independently externally validate two prediction models, one developed by the CRASH (Corticosteroid Randomization After Significant Head injury) trial investigators, and the other from the IMPACT (International Mission for Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury) group. We used a cohort of 300 patients with severe TBI (GCS ≤ 8) consecutively admitted to the National Neuroscience Institute (NNI), Singapore, between February 2006 and December 2009. The CRASH models (base and CT) predicts 14-day mortality and 6-month unfavourable outcome. The IMPACT models (core, extended and lab) estimates 6-month mortality and unfavourable outcome. Validation was based on measures of discrimination and calibration, discrimination was assessed using the area under the receiving operating characteristic curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (H-L) goodness-of-fit test and Cox calibration regression analysis. In the NNI database, the overall observed 14-day mortality was 47.7% and the observed 6-month unfavourable outcome was 71.0%. The CRASH base model and all three IMPACT models gave an underestimate of the observed values in our cohort when used to predict outcome. Using the CRASH CT model, the predicted 14-day mortality of 46.6% approximated the observed outcome, while the predicted 6-month unfavourable outcome was an over-estimate at 74.8%. Overall both the CRASH and IMPACT models showed good discrimination, with AUCs ranging from 0.80 to 0.89, and good overall calibration. We conclude that both the CRASH and IMPACT models satisfactorily predicted outcome in our patients with severe TBI.

Language: en