Psychological Predictors of Fitness to Drive Judith Leung University of Wollongong
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University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections 2004 Psychological predictors of fitness to drive Judith Leung University of Wollongong Recommended Citation 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 Research Online is the open access institutional repository for the University of Wollongong. For further information contact Manager Repository Services: [email protected]. Psychological Predictors of Fitness to Drive A thesis submitted in partial fulfillment of the requirements for the award of the degree Doctor of Psychology From UNIVERSITY OF WOLLONGONG by Judith Leung (B.Sc.(Hons)) Faculty of Health and Behavioural Sciences 2004 11 Thesis certification I, Judith Leung, declare that this thesis, submitted in partial fulfillment of the requirements for the award of Doctor of Psychology, in the Department of Health and Behavioural Sciences, University of Wollongong, is wholly my own work unless otherwise referenced or acknowledged. The document has not been submitted for qualification at any other academic institution. Judith Leung iii ABSTRACT In the state of New South Wales, standardised assessment procedures for the re examination 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 of the battery can predict the total number of interventions and pass/fail measures of the on- road driving test; (ii) executive function tests will significantly predict of the total number 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 iv 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 tests 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 in 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. V ACKNOWLEDGEMENT My deepest thanks go to my mother and father, who never gave up on the belief that I have undersold myself, and was yet to realise my full potential. Thank you dad, for your brilliant intellect, your free thinking, and the challenges that you have set for me in life. Thank you mum, for your emotional and financial support, your dedication, and your humour. I thank both of my supervisors, Professor Frank Deane and Dr. Vida Bliokas, without whose assistance I would not have completed my thesis. Thank you Frank, for being persistent, unrelenting, brutally direct, unwaveringly keeping me on track and not giving up on me. I have been repeatedly challenged, and have learned substantially from your tremendous input. Thank you Vida, for your words of encouragement, clarity in thinking, your ability to stick to a point, the endless reviews and critical analyses, and the personal time sacrificed to read my work. I must have been at times a pain in the neck for both of you, but it is to you both that I am eternally indebted. To Christine Brumby, I thank you for the extra effort you have put in for my research. To Jo Taylor, thank you for the use of your unpublished data. And many thanks to all the psychologists and occupational therapists who have participated in this research. To my ex-husband, Phil, I am truly sorry. To Ronan, my son, you are a beautiful, deep and intense person within. It is also in you to do all that I have done in life and more. You are your mother's son. I hope that one day you will find your path. To Sitah, thank you for being such a beautiful, thoughtful, caring, responsible, and loving daughter. You are a dream child. I hope that one day you will be able to break free of the shackles that hold you to being 'good'. You do not need to compensate for all that has gone wrong. You are free to be yourself. To Mike Reed, thank you for being my mentor, my cheerleader, and my support. Thank you for inviting me to join you in a new venture, and for shouldering the load at the critical time of establishing a new training course and centre. How can I begin to return the favour? VI And finally, to my great grandfather, Au Zhian Sum, Personal Tutor and Advisor to Emperor Aisin-Gioro Puyi, and my other ancestors, whose stories and journeys in life, courage, and system of honour, have deeply inspired me to reach for the limits, and uphold lineal traditions. Let me salute you all. vii Table of Contents Thesis Certification ii Abstract iii Acknowledgements v Table of Contents vii List of Tables xi List of Diagrams xi INTRODUCTION 1 CHAPTER 1 DRIVING AND DRIVING COMPETENCE 3 1.1 The Role of Driving in Our Society 3 1.2 Costs of Incompetent Driving 4 1.3 Sources of Dangerous Driving Behaviour 5 1.3.1 External Factors 5 1.3.2 Internal Factors 6 1.3.2.1 Age 6 1.3.2.2 Speed and Fatigue 7 1.3.2.3 Alcohol and Other Drugs 7 1.3.2.4 Personality Style 8 1.3.2.5 Cognitive and Other Impairments 8 1.4 Driving Research and Methodological Issues 10 1.4.1 Area of Focus 10 1.4.2 Methodologies 11 1.4.3 Outcome Measures 12 CHAPTER 2 MODELS OF DRIVING 14 2.1 Motivational Models 14 2.2 Information Processing Models 15 2.3 The Cybernetic Model 17 2.4 Hierarchical Control Models 18 2.4.1 Skill-Rule-Knowledge-Judgement Model 19 2.4.2 The Three Level Hierarchical Model 19 2.5 Factors Affecting Driving 21 Vlll CHAPTER 3 COGNITIVE IMPAIRMENT AND DRIVING 23 3.1 Cognitive Function and Driving 23 3.2 Assessment of Cognitive Function 26 3.3 The Relationship Between Neuropsychological Test Batteries and Driving....39 3.4 The Relationship Between Individual Neuropsychological Tests and Driving 41 3.5 Executive Functions 44 3.6 Executive Functions and Driving Behaviour 45 3.7 Other Psychological Factors Affecting Driving 49 CHAPTER 4 ASSESSMENT OF DRIVING COMPETENCE 53 4.1 Driving Assessment in NSW 53 4.2 Validity of RTA Driving Assessment 54 4.3 Driving Assessment for the Cognitively Impaired 55 4.4 Austroads Guidelines for Driving Assessment 55 4.5 Standardised Assessment for Driving 58 4.6 Driving Assessment Components 60 4.7 The Present Study 62 CHAPTER 5 METHODOLOGY 64 5.1 Introduction 64 5.2 Participants 64 5.3 Materials 66 5.3.1 Neuropsychological Measures 66 5.3.1.1 Judgement of Line Orientation Test 66 5.3.1.2 Visual Form Discrimination Test 67 5.3.1.3 Trail Making Tests 68 5.3.1.4 WAIS-R Picture Arrangement 68 5.3.1.5 WAIS-R Digit Symbol Substitution 69 5.3.1.6 WAIS-R Block Design 70 5.3.1.7 Rey-Osterreith Complex Figure Test 70 5.3.1.8 Rey Auditory Verbal Learning Test 71 5.3.1.9 Wisconsin Card Sort Test 72 5.3.1.10 Cut-Off Scores for Tests 73 5.3.1.11 Pass/Borderline/Fail Criterion for Neuropsychological Assessment 74 5.3.2 Anxiety Measures 75 5.3.2.1 State-Trait Anxiety Inventory - 6 75 5.3.2.2 Test Anxiety Inventory - 5 ..75 5.3.2.3 Other Anxiety Measures 76 IX 5.3.3 Off-Road Occupational Therapy Assessment 77 5.3.3.1 Vision Screen 77 5.3.3.2 Physical Screen ...77 5.3.3.3 Road Law Written 77 5.3.3.4 Road Law Visual 77 5.3.3.5 Visual Recognition Slide Test 78 5.3.4 On-Road Driving Test 78 5.4 Procedures 80 5.5 Analytical Procedures 85 5.5.1 Main Study 86 5.5.2 Anxiety and Driving Assessment 89 CHAPTER 6 RESULTS 91 6.1 Neuropsychological Testing of Driving Suitability ..91 6.1.1 Neuropsychological Tests and Driving Outcome Measures 93 6.1.2 Neuropsychological Test Battery and Driving Outcome Measures..