Research Platform
Issue Date: August 2016
Published Online: August 01, 2016
Updated: January 01, 2021
Driving and Parkinson's Disease: What Only Caregivers Can Tell Us
Author Affiliations
  • University of Western Ontario
  • University of Western Ontario
Article Information
Community Mobility and Driving / Neurologic Conditions / Parkinson's Disease / Assessment/Measurement
Research Platform   |   August 01, 2016
Driving and Parkinson's Disease: What Only Caregivers Can Tell Us
American Journal of Occupational Therapy, August 2016, Vol. 70, 7011500005.
American Journal of Occupational Therapy, August 2016, Vol. 70, 7011500005.

Date Presented 4/9/2016

Early identification of at-risk drivers with Parkinson’s disease (PD) is critical for baseline fitness-to-drive assessments. We demonstrated that fitness-to-drive predictions by caregivers of drivers with PD, combined with the Trails B test, are accurate screening tools in identifying at-risk drivers.

Primary Author and Speaker: Liliana Alvarez

Additional Speaker: Sherrilene Classen

PURPOSE: We investigated whether caregivers of drivers with Parkinson’s disease (PD) could predict the driver’s on-road assessment outcome and whether the predictive value of their impressions differed from that of drivers themselves, that of their neurologist, or information provided by standardized predictive clinical measures of divided attention (Useful Field of View® [UFOV]) and set shifting (Trails B), using the on-road assessment as the gold standard.
BACKGROUND: In Western societies, driving represents seniors’ primary mode of transportation and symbolizes independence and autonomy. PD is a age-related, progressive, neurodegenerative disorder that can significantly impair driving. At-risk drivers with PD need to be identified as early as possible in order to access adequate assessment and intervention strategies.
DESIGN: Drivers with PD (N = 99) participated in this prospective study, which included clinical and on-road assessments. The drivers’ neurologists or movement disorder (MD) specialists and caregivers also participated in this study.
METHOD: We obtained participants’ demographic information including age, gender, and number of years experiencing PD symptoms. A neurologist/MD specialist evaluated each participant using the motor subscale of the Unified Parkinson’s Disease Rating Scale (UPDRS Part 3) and the modified Hoehn and Yahr categorical scale to determine disease severity. We obtained the driver, neurologist, and caregiver risk impression (asking each if they thought the driver would pass or fail the on-road assessment). After completing the UFOV and Trails B tests, participants completed the on-road assessment.
ANALYSIS: We used t test and χ2 to perform comparisons between the two subgroups (pass vs. fail) for clinical variables as well as risk impressions. After descriptive and univariate analysis, we used logistic regression to model the clinical variables (UFOV RI and Trails B) as well as driver, physician, and caregiver risk impressions.
RESULTS: When compared with drivers with PD who passed (n = 58), those who failed (n = 41) were older, more impaired as determined by their Hoehn and Yahr scores, and further along in their disease progression as measured by disease severity. Also, those who failed the on-road assessment had poorer UFOV RI and Trails B scores. In the regression model, caregivers’ risk impressions (odds ratio [OR] = 13.75, p = .03) and Trails B (OR = .41, p = .02) emerged as the only significant predictors of passing the on-road assessment. Keeping all the other covariate variables fixed in the model, participants had a 13.75 times higher odds to pass the on-road assessment when the caregiver predicted they would than when the caregiver didn’t. In addition, increased duration for completing Trails B was associated with decreased likelihood of passing the on-road assessment. Again, keeping all the other covariates fixed, a one-unit (second) increase in Trails B reduced the odds of passing the on-road assessment by 40%.
DISCUSSION: At-risk drivers with PD need to be identified as earlier as possible in order to access adequate driving assessment and/or intervention. Our findings suggest that apart from Trails B, caregivers may be a valuable resource who can help identify potentially at-risk drivers with PD who may benefit from a comprehensive driving assessment.
IMPACT STATEMENT: Occupational therapists may consider including caregivers to detect at-risk driving performance in those with PD. Caregiver impressions, combined with a measure of set shifting, may be used as an efficient screening to identify drivers with PD who are potentially at risk for failing an on-road assessment.