Doctor of Psycology
Faculty of Health and Behavioural Sciences
Leung, Judith, Psychological predictors of fitness to drive, Doctor of Psycology thesis, Faculty of Health and Behavioural Sciences, University of Wollongong, 2004. http://ro.uow.edu.au/theses/2135
In the state of New South Wales, standardised assessment procedures for the reexamination of the competence to drive for individuals with cognitive impairment are not available. This study aims to validate a neuropsychological test battery used by Port Kembla Rehabilitation Team and the Illawarra Brain Injury Service. It is proposed that validation of this battery of neuropsychological tests can represent the first step toward standardisation.
The first aim of this study was to examine the relationship between neuropsychological tests and driving outcome by comparing the results of the neuropsychological tests to two on-road driving outcomes. The second aim was to investigate the role of executive functions in predicting driving performance. The third aim was to explore the role of anxiety on driving behaviour. Specifically, the hypotheses were: (i) a relationship exists between the neuropsychological test battery and driving test outcome, and that the results the battery can predict the total number of interventions and pass/fail measures of the driving test; (ii) executive function tests will significantly predict of the total of interventions and pass/fail measures of the on-road driving test; (iii) anxiety is the consequence rather than the cause of poor driving performance for individuals with cognitive impairment.
One hundred and four individuals with cognitive impairment were administered 10 neuropsychological tests, and 35 were given anxiety measures before and after an on-road driving test. Correlation analyses showed a relationship between most of the neuropsychological tests and the driving outcome measures. Standard multiple regression and logistic regression analyses showed the neuropsychological test battery was able to correctly classify 74% of the pass/fail outcome rates and accounted for 18% of the variance in the total number of interventions. However, when the effectiveness of the individual was examined, only the Rey-Osterreith Complex Figure Test was able to predict pass/fail driving outcome classification.
Factor analysis did not support the delineation of executive function tests from the general cognitive function tests in this test battery. Therefore, the role of executive function driving could not be examined. Contrary to predictions, correlation analyses, ANOVA, and repeated t-tests indicated anxiety was related to better driving performance rather than being the consequence of poor driving performance. The result is consistent with curvilinear relationships often found between anxiety and performance.
Recommendations were made to improve measurements of executive functions for future research. The findings have implications for the development of a standardised assessment procedure for the re-assessment of the competence to drive for those with cognitive impairment.