Cognitive and personality determinants of post-injury driving fitness

Increasingly often, practitioners in neuropsychological rehabilitation centers are called upon to assess patients' fitness to drive after brain injury. There is, therefore, a need for valid and reliable psychometric test batteries that enable unsafe drivers to be identified. This article investigates the contribution of five driving-related personality traits to the prediction of fitness to drive in patients suffering from traumatic brain injuries (TBI) or strokes over and above cognitive ability traits that have already shown to be related to safe driving. A total of 178 patients suffering from either strokes or TBI participated in this study. All the participants completed a standardized psychometric test battery and subsequently took a standardized driving test. The contribution of the driving-related ability and personality traits to the prediction of fitness to drive was investigated by means of a logistic regression analysis and an artificial neural network. The results indicate that both cognitive ability and personality factors are important in predicting fitness to drive, although cognitive ability factors contribute slightly more to the prediction of patients' actual fitness to drive than personality factors. Furthermore, even though there are subtle differences in the predictive models obtained for the two subsamples (stroke and TBI patients), these differences are adequately accounted for by a more unitary model calculated by means of an artificial neural network that is capable of taking account of moderating effects between the predictor variables.