Predicting outcome after traumatic brain injury: development and international validation of prognostic scores based on admission characteristics
BACKGROUND: Traumatic brain injury (TBI) is a leading cause of death and disability. A reliable prediction of outcome on admission is of great clinical relevance. We aimed to develop prognostic models with readily available traditional and novel predictors. METHODS & FINDINGS: Prospectively collected individual patient data were analyzed from 11 studies. We considered predictors available at admission in logistic regression models to predict mortality and unfavorable outcome according to the Glasgow Outcome Scale at 6 months after injury. Prognostic models were developed in 8509 patients with severe or moderate TBI, with cross-validation by omitting each of the 11 studies in turn. External validation was on 6681 patients from the recent MRC CRASH trial. We found that the strongest predictors were age, motor score, pupillary reactivity and CT characteristics including the presence of traumatic subarachnoid hemorrhage. A prognostic model that combined age, motor score, and pupillary reactivity had an area under the receiver operating characteristic curve (AUC) between 0.66 and 0.84 at cross-validation. This performance could be improved (AUC increase approximately 0.05) by considering CT characteristics, secondary insults (hypotension, hypoxia), and laboratory parameters (glucose and hemoglobin). External validation confirmed the adequate discriminative ability (AUC 0.80). Outcomes were systematically worse than predicted, but less so in 1588 patients from high income countries in the CRASH trial. CONCLUSIONS: Prognostic models using baseline characteristics provide adequate discrimination between patients with good and poor 6 month outcomes after TBI, especially if CT and laboratory findings are considered in addition to traditional predictors. The model predictions may support clinical practice and research, including the design and analysis of randomised controlled trials.
|Persistent URL||dx.doi.org/10.1371/journal.pmed.0050165, hdl.handle.net/1765/12936|
Steyerberg, E.W., Mushkudiani, N., Perel, P., Butcher, I., Lu, J., McHugh, G.S., … Maas, A.I.R.. (2008). Predicting outcome after traumatic brain injury: development and international validation of prognostic scores based on admission characteristics. PLoS Medicine, 5(8), 1251–1261. doi:10.1371/journal.pmed.0050165