Self-awareness and return to driving after traumatic brain injury

Traumatic Brain Injury (TBI) is a leading cause of disability in young adults and can severely impact everyday functioning. An important goal for many individuals with TBI is to make a return to driving. Post injury impairments may affect driving ability, resulting in a need for assessment and, in some cases, further rehabilitation. A common problem following TBI that has previously been implicated in fitness for return to driving is impaired self-awareness. Research exploring the role of awareness has been limited, however, and fraught with methodological limitations. The aim of this thesis was therefore to firstly develop a measure of awareness of on-road driving ability for use in return to driving assessments in brain injured populations; secondly, to use this measure to explore the characteristics and relationships of awareness of driving in individuals with TBI and healthy controls; and finally to explore the nature and extent of self-regulatory behaviour in individuals with TBI deemed fit to resume driving. Participants included 39 individuals with moderate to extremely severe TBI and 59 healthy age, gender and education matched controls. Participants completed neuropsychological tests, a standardised on-road driving assessment and the Brain Injury Driving Self-Awareness Measure (BIDSAM), and questionnaires on driving habits and behaviour at three time points, relating to premorbid driving, anticipated driving post injury and driving at three months post on-road assessment. The first study describes the development and validation of the BIDSAM, which is a new tool designed to assess awareness of on-road driving ability. The measure is completed by participants and clinicians and a discrepancy score is calculated to assess differences in ratings of driving ability between self and clinician opinions. The results of this study indicated that the BIDSAM self, clinician and awareness scales have very good levels of internal consistency. Criterion-related validity was established through significant correlations between clinician ratings and on-road driving performance. Furthermore, convergent validity was established through significant correlations between the BIDSAM awareness scales and an existing measure of self-awareness. The second study aimed to explore the differences in awareness of driving between individuals with TBI deemed fit and unfit to resume driving and healthy controls, in addition to examining the correlates of awareness and self-ratings of ability. The result of this investigation revealed that individuals who failed the on-road assessment significantly overestimated their driving abilities relative to controls and individuals with TBI who passed. Furthermore, poor awareness was associated with reduced cognitive functioning while poor self-ratings of driving ability were associated with symptoms of anxiety and depression. The third study explored the driving habits and self-regulatory practices of individuals with TBI who made a successful return to driving. Relative to controls, individuals with TBI expected greater reductions in their driving frequency and increases in their driving avoidance upon returning to driving. At three month follow up, individuals with TBI reported consistent reductions in their overall driving frequency but only circumscribed increases in avoidance. Changes in driving frequency and avoidance were associated with the female gender and anxiety. These findings suggest overall that awareness is a significant factor in fitness to drive and more severe cognitive impairments may be a risk factor for impaired awareness of driving. As such, clinicians may need to assess awareness of driving as part of return to driving assessments, in order to identify individuals who overestimate their abilities. These individuals may require additional support and rehabilitation prior to resuming driving. Interestingly, the factors associated with how individuals perceive their driving abilities and subsequently regulate their driving were almost entirely subjective in nature and this suggests that clinicians must consider the contribution of psychological factors such as anxiety when providing recommendations and feedback for driving. The fact that individuals with TBI acknowledged a need to change their driving habits and later reported having followed through with their intentions, suggests that these individuals may be open to recommendations by clinicians to enhance their self-regulatory behaviour and compensatory strategies in order to facilitate their safe return to driving post injury. Together, the findings of this thesis extend the literature on awareness and driving after brain injury and provide the first dedicated driving-related measure of awareness for use by clinicians in return to driving assessments