Self-Regulatory Driving Behaviour, Perceived Abilities and Comfort Level of Older Drivers with Parkinson’s disease compared to Age-Matched Controls by Alexander Michael Crizzle A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Health Studies and Gerontology - Aging, Health and Well-Being Waterloo, Ontario, Canada, 2011 © Alexander Michael Crizzle 2011 Declaration I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract Introduction: Multiple studies have shown the symptoms of Parkinson‟s disease (PD) can impair driving performance. Studies have also found elevated crash rates in drivers with PD, however, none have controlled for exposure or amount of driving. Although a few studies have suggested that drivers with PD may self-regulate (e.g., by reducing exposure or avoiding challenging situations), findings were based on self-report data. Studies with healthy older drivers have shown that objective driving data is more accurate than self-estimates. Purposes: The primary objectives of this study were to examine whether drivers with PD restrict their driving (exposure and patterns) relative to an age-matched control group and explore possible reasons for such restrictions: trip purposes, perceptions of driving comfort and abilities, as well as depression, disease severity and symptoms associated with PD. Methods: A convenience sample of 27 drivers with PD (mean 71.6±6.6, range 57 to 82, 78% men) and 20 age-matched control drivers from the same region (70.6±7.9, range 57 to 84, 80% men) were assessed between October 2009 and August 2010. Driving data was collected for two weeks using two electronic devices (one with GPS) installed in each person‟s vehicle. Participants completed trip logs, questionnaires on background and usual driving habits, and measures of cognitive functioning, depression, quality of life, daytime sleepiness, driving comfort and abilities. Contrast sensitivity and brake response time were also assessed. Severity of PD was assessed using the Unified Parkinson‟s Disease Rating Scale (UPDRS) motor scores. An interview was conducted at the end of the second assessment to examine influence of the devices, driving problems and any departures from usual patterns over the monitoring period. Results: Of the 128 PD patients screened for possible study participation, 35% had already stopped driving. Former drivers were older, more likely to be women and had poorer UPDRS iii motor scores. Only 48% of those who were eligible for the study agreed to participate. Compared to controls, the PD group had significantly slower brake response times, higher depression and quality of life scores, less comfort driving at night and poorer perceptions of their driving abilities. The PD group also had significantly lower cognitive functioning scores than controls, and a significantly greater proportion (74% versus 45%) were classified as having mild cognitive impairment. Compared to vehicle recordings, both groups mis-estimated the amount they drove over two weeks (measurement error was 94 km for the PD group and 210 km for the controls). The PD group drove significantly less overall (days, trips, distance and duration), at night, on week-ends and in bad weather and for different purposes. Four of the PD drivers had minor accidents over the two weeks, while one lost his license. Conclusions: Self-estimates of exposure were inaccurate warranting the continued use of objective driving data. Overall, the findings suggest that drivers with PD appear to restrict their driving exposure and patterns relative to controls. The PD group were more likely to combine several activities into one trip, possibly due to fatigue. Moreover, they were more likely than controls to drive for medical appointments and less likely to drive for leisure activities and make out of town trips. The findings need to be replicated with larger samples and longer monitoring periods to examine changes in self-regulatory practices associated with disease progression and symptomatology. Other researchers are also likely to have similar difficulty in recruiting drivers with PD as this group may quit driving at an earlier age and those who are still driving are fearful of being reported to licensing authorities. Future studies also need to screen for cognitive impairment which often goes undetected, particularly in otherwise healthy drivers. iv Acknowledgments I would like to acknowledge several individuals who have provided invaluable support throughout this project and over the past 5 years at the University of Waterloo. First, I would like to extend my gratitude to Dr. Anita Myers, my supervisor, for her tireless dedication, guidance and support throughout the completion of my PhD degree. I am truly appreciative of her efforts and time in helping me achieve my goals. She truly has a passion for teaching and mentoring all her students. I believe with her help, I have become a better researcher over my graduate years at Waterloo. I would also like to thank my committee members, Dr. Quincy Almeida, Dr. Brenda Vrkljan and Dr. Eric Roy for your willingness share your expertise and input which greatly contributed to the completion of this project. I would also like to acknowledge the external examiner, Dr. Mary Jenkins, whose advice and interest in the project was invaluable. I would also like to acknowledge the Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive) and the Schlegel Research Institute of Aging (RIA) for providing funding for this project. Finally, I would like to thank my parents, Renate and William Crizzle, for their support, encouragement and for all their love. As parents, you have shaped me into who I am and I thank-you for that. I wouldn‟t be where I am today without you. And lastly, to my fiancée Joanne Gierlach, you have always been the rock I‟ve leaned on, always providing confidence and a comforting smile. You truly inspire me to do great things. Alex Crizzle University of Waterloo May, 2011 v Table of Contents Author’s Declaration .............................................................................................. ii Abstract ................................................................................................................... iii Acknowledgements................................................................................................... v Table of Contents ................................................................................................... vi List of Figures ......................................................................................................... xi List of Tables ......................................................................................................... xii Chapter 1: Introduction .......................................................................................... 1 1.1 Statement of the Problem ...........................................................................................................2 1.2 Parkinson‟s Disease ...................................................................................................................4 1.3 Role of Licensing Authorities and Physicians ...........................................................................6 1.4 Self-Regulation ..........................................................................................................................8 1.5 Summary and Overview ..........................................................................................................11 Chapter 2: Literature Review ............................................................................... 13 2.1 Introduction ............................................................................................................................. 13 2.2 Studies on Older Drivers in General ....................................................................................... 14 2.2.1 Performance ................................................................................................................ 14 2.2.2 Exposure ..................................................................................................................... 15 2.2.3 Patterns ....................................................................................................................... 16 2.2.4 Factors Associated with Self-Regulation ................................................................... 17 2.3 Studies on Drivers with PD..................................................................................................... 19 2.3.1 Crash Rates ................................................................................................................. 19 2.3.2 Driving Errors ............................................................................................................. 20 2.3.3 Factors Associated with Driving Performance ........................................................... 21 2.3.4 Driving Restrictions and Cessation ............................................................................ 23 2.4 Summary and Implications ..................................................................................................... 24 vi Chapter 3: Methods ..............................................................................................