Fitness to drive after acquired brain injury: Results from patient cognitive screening and on-road assessment compared to age-adjusted norm values

Self-awareness predicts fitness to drive among adults referred to occupational therapy evaluation

Background

Driving is associated with independence, well-being, quality of life, and an active lifestyle. Driving requires cognitive, motor, and visual skills, including self-awareness and processing speed. This study examines whether driver self-awareness, motor processing speed, and cognitive processing speed can predict fitness to drive among individuals referred to occupational therapy evaluation due to concerns about their driving ability.

Method

In this cross-sectional study, 39 participants were referred to off- and on-road driving evaluation to determine their fitness to drive due to changes in health status, advanced age, license renewal requirement, or prior automobile accidents. A registered occupational therapist (OT) classified 23 of the participants as fit to drive and 16 as unfit to drive. Motor and cognitive processing speed were assessed by the Stationary Perception-Reaction Timer and the Color Trails Test, respectively. Driving self-awareness was assessed by comparing the DI and OT evaluations to the participants' estimation of their own on-road driving performance.

Results

The fit-to-drive participants had a better motor and cognitive processing speed than those unfit-to-drive. The unfit-to-drive group overestimated their driving ability, whereas the fit-to-drive group accurately or almost accurately estimated their driving ability. Driving self-awareness was a significant predictor of participants' fitness to drive.

Conclusions

This study demonstrates the importance of self-awareness for predicting fitness to drive among people at risk for compromised driving skills. Thus, driving self-awareness should be addressed as part of fitness-to-drive evaluations and interventions.

Usability of Norm Values on Results from a Simulator Device and Cognitive Tests in Traffic Medicine

Introduction

Driving is an essential everyday task for most adults, and fitness to continue car-driving after a brain injury/disease is a common issue in rehabilitation settings. There is no consensus on how this assessment should be performed and thus further research and development are of great value. The aim was to study the usability of cut-off values, based on recently developed norm values for a driving simulator device (CyberSiM), as well as cognitive tests, for patients already considered fit-to-drive after a standardized traffic medical investigation.

Methods

The study had a retrospective case-control design. Norm results (n = 129) were compared with patient results (n = 126) divided into two age groups (≤59 years and ≥60 years). Results from Useful Field of View, Trail Making Test, Nordic Stroke Driver Screening Assessment as well as a simulator device (CyberSiM) were compared.

Results

The group of patients considered fit-to-drive after a traffic medicine assessment had worse results on all cognitive tests compared with norms. Results on CyberSiM subtests II and III did not differ from norms. The proportion of patients within suggested cut-off limits (mean±2SD norm) and considered fit to drive (mean±2SD norm) were highest (75–95%) for all three subtests of CyberSiM and for Useful Field of View in both age groups.

Conclusion

Availability of norm values in decision on continued driving is of value when interpreting the results of cognitive assessments sensitive to age, but it must be handled with care because many factors are important for individuals’ ability to drive.