Assessing Fitness to Drive in Patients With Different Types of Dementia.

Dementia is a risk factor for unsafe driving. Therefore, an assessment strategy has recently been developed for the prediction of fitness to drive in patients with the Alzheimer disease (AD). The aim of this study was to investigate whether this strategy is also predictive of fitness to drive in patients with non-AD dementia, that is, vascular dementia, frontotemporal dementia, and dementia with Lewy bodies. Predictors were derived from 3 types of assessment: clinical interviews, neuropsychological tests, and driving simulator rides. The criterion was the pass-fail outcome of an official on-road driving assessment. About half of the patients with non-AD dementia (n=34) failed the on-road driving assessment. Neuropsychological assessment [area under the curve (AUC)=0.786] was significantly predictive of fitness to drive in patients with non-AD dementia, however, clinical interviews (AUC=0.559) and driving simulator rides (AUC=0.404) were not. The fitness-to-drive assessment strategy with the 3 types of assessment combined (AUC=0.635) was not found to significantly predict fitness to drive in non-AD dementia. Different types of dementia require different measures and assessment strategies.

Predictive Value of the Esterman Visual Field Test on the Outcome of the On-Road Driving Test.

Purpose: As the prevalence of age-related visual field disorders and the number of older drivers are rising, clear criteria on visual field requirements for driving are important. This article explores the predictive value of the Esterman visual field in relation to the outcome of an on-road driving test. Methods: A retrospective chart review was performed for driver's license applicants who, based on their visual field, performed an on-road driving test. Cases (N = 101) with a failed on-road driving test were matched with 101 controls with a passed outcome. The Esterman visual field was divided in regions, and the number of points missed per region was counted. Logistic regression models and receiver operating characteristic (ROC) curves were computed for each region. Results: Most regions presented a significantly increased odds for failing the driving test when more points were missed. The odds ratio for the whole visual field was 2.52 (95% confidence interval, 1.53-4.14, P < 0.001) for all the participants. However, ROC curves failed to reveal distinct fail-pass criteria based on the number of points missed, as revealed by a large amount of overlap between cases and controls. Conclusions: These findings confirm the relation between visual field damage and impaired driving performance. However, the Esterman visual field results were not conclusive for predicting the driving performance of the individual driver with visual field defects. Translational Relevance: In our group of participants, the number of on-road driving tests cannot be further reduced by a more detailed definition of fail-pass criteria, based on the Esterman visual field test.

Driving Difficulties Among Patients with Alzheimer's Disease and Other Neurodegenerative Disorders.

BACKGROUND/OBJECTIVE: Neurodegenerative disorders impact fitness to drive of older drivers, but on-road driving studies investigating patients with different neurodegenerative disorders are scarce. A variety of driving errors have been reported in patients with Alzheimer's disease (AD), but it is unclear which types of driving errors occur most frequently. Moreover, patients with other neurodegenerative disorders than AD typically present with different symptoms and impairments, therefore different driving errors may be expected. METHODS: Patients with AD (n = 80), patients with other neurodegenerative disorders with cognitive decline (i.e., vascular dementia, frontotemporal dementia, dementia with Lewy bodies/Parkinson's disease, n = 59), and healthy older drivers (n = 45) participated in a fitness-to-drive assessment study including on-road driving. RESULTS: Patients with AD performed significantly worse than healthy older drivers on operational, tactical, visual, and global aspects of on-road driving. In patients with AD, on-road measures were significantly associated with 'off-road' measures. Patients with neurodegenerative disorders other than AD showed large overlap in the types of driving errors. Several driving errors were identified that appear to be characteristic for patients with particular neurodegenerative disorders. CONCLUSION: Patients from each group of neurodegenerative disorders commonly display tactical driving errors regarding lane positioning, slow driving, observation of the blind spot, and scanning behavior. Several other tactical and operational driving errors, including not communicating with cyclists and unsteady steering, were more frequently observed in patients with non-AD neurodegenerative disorders. These findings have implications for on-road and 'off-road' fitness-to-drive assessments for patients with neurodegenerative disorders with cognitive decline.

Assessing fitness to drive-A validation study on patients with mild cognitive impairment.

OBJECTIVES: There is no consensus yet on how to determine which patients with cognitive impairment are able to drive a car safely and which are not. Recently, a strategy was composed for the assessment of fitness to drive, consisting of clinical interviews, a neuropsychological assessment, and driving simulator rides, which was compared with the outcome of an expert evaluation of an on-road driving assessment. A selection of tests and parameters of the new approach revealed a predictive accuracy of 97.4% for the prediction of practical fitness to drive on an initial sample of patients with Alzheimer's dementia. The aim of the present study was to explore whether the selected variables would be equally predictive (i.e., valid) for a closely related group of patients; that is, patients with mild cognitive impairment (MCI). METHODS: Eighteen patients with mild cognitive impairment completed the proposed approach to the measurement of fitness to drive, including clinical interviews, a neuropsychological assessment, and driving simulator rides. The criterion fitness to drive was again assessed by means of an on-road driving evaluation. The predictive validity of the fitness to drive assessment strategy was evaluated by receiver operating characteristic (ROC) analyses. RESULTS: Twelve patients with MCI (66.7%) passed and 6 patients (33.3%) failed the on-road driving assessment. The previously proposed approach to the measurement of fitness to drive achieved an overall predictive accuracy of 94.4% in these patients. The application of an optimal cutoff resulted in a diagnostic accuracy of 100% sensitivity toward unfit to drive and 83.3% specificity toward fit to drive. Further analyses revealed that the neuropsychological assessment and the driving simulator rides produced rather stable prediction rates, whereas clinical interviews were not significantly predictive for practical fitness to drive in the MCI patient sample. CONCLUSIONS: The selected measures of the previously proposed approach revealed adequate accuracy in identifying fitness to drive in patients with MCI. Furthermore, a combination of neuropsychological test performance and simulated driving behavior proved to be the most valid predictor of practical fitness to drive.

Prediction of Fitness to Drive in Patients with Alzheimer's Dementia.

The number of patients with Alzheimer's disease (AD) is increasing and so is the number of patients driving a car. To enable patients to retain their mobility while at the same time not endangering public safety, each patient should be assessed for fitness to drive. The aim of this study is to develop a method to assess fitness to drive in a clinical setting, using three types of assessments, i.e. clinical interviews, neuropsychological assessment and driving simulator rides. The goals are (1) to determine for each type of assessment which combination of measures is most predictive for on-road driving performance, (2) to compare the predictive value of clinical interviews, neuropsychological assessment and driving simulator evaluation and (3) to determine which combination of these assessments provides the best prediction of fitness to drive. Eighty-one patients with AD and 45 healthy individuals participated. All participated in a clinical interview, and were administered a neuropsychological test battery and a driving simulator ride (predictors). The criterion fitness to drive was determined in an on-road driving assessment by experts of the CBR Dutch driving test organisation according to their official protocol. The validity of the predictors to determine fitness to drive was explored by means of logistic regression analyses, discriminant function analyses, as well as receiver operating curve analyses. We found that all three types of assessments are predictive of on-road driving performance. Neuropsychological assessment had the highest classification accuracy followed by driving simulator rides and clinical interviews. However, combining all three types of assessments yielded the best prediction for fitness to drive in patients with AD with an overall accuracy of 92.7%, which makes this method highly valid for assessing fitness to drive in AD. This method may be used to advise patients with AD and their family members about fitness to drive.

Car driving performance in hemianopia: an on-road driving study.

PURPOSE: To study driving performance in people with homonymous hemianopia (HH) assessed in the official on-road test of practical fitness to drive by the Dutch driver's licensing authority (CBR). METHODS: Data were collected from a cohort (January 2010-July 2012) of all people with HH following the official relicensure trajectory at Royal Dutch Visio and the CBR in the Netherlands. Driving performance during the official on-road tests of practical fitness to drive was scored by professional experts on practical fitness to drive, using the visual impairments protocol and a standardized scoring of visual, tactical and operational aspects. Age ranged from 27 to 72 years (mean = 52, SD = 11.7) and time since onset of the visual field defect ranged from 6 to 41 months (mean = 15, SD = 7.5). RESULTS: Fourteen (54%) participants were judged as fit to drive. Besides poor visual scanning during driving, specific tactical, and operational weaknesses were observed in people with HH that were evaluated as unfit to drive. Results suggest that judgement on practical fitness to drive cannot be based on solely the visual field size. Visual scanning and operational handling of the car were found to be more impaired with longer time not driven, while such an effect was not found for tactical choices during driving. CONCLUSIONS: Training programs aimed at improving practical fitness to drive in people with HH should focus on improving both visual scanning, as well as driving aspects such as steering stability, speed adaptation, and anticipating environmental changes.

The Introduction of Bioptic Driving in The Netherlands.

BACKGROUND: In many states of the U.S.A., people with moderately reduced visual acuity e.g., 20/50 - 20/200) can legally drive with the aid of a small, spectacle-mounted ("bioptic") telescope. We conducted a demonstration project to assess the viability of implementing bioptic driving in The Netherlands. In this paper we describe the framework of the project from conception through to realization of our primary objective - the introduction of bioptic driving as a legal option for visually impaired people in The Netherlands. METHODS: The project was based on bioptic driving programs in the U.S.A., which were adapted to fit within current driving training and assessment practices in The Netherlands. The project convened a consortium of organizations including the Netherlands Bureau of Driving Skills Certificates (CBR), service organizations for the visually impaired, and research departments at universities investigating driving and vision. All organizations were educated about bioptic driving and participating professionals were trained in their specific aspects of the project. Media publicity led to significant interest and helped recruitment that enabled the screening and selection of potential participants. OUTCOMES: The project demonstrated that people with moderately reduced visual acuity can be trained to achieve an adequate level of proficient and safe driving (as assessed by the local official driving licensing professionals) when using a bioptic telescope for the road conditions in the Netherlands. Based on the successful project outcomes, a request was made to the Minister to allow bioptic driving in the Netherlands. This request has been accepted; the legal procedures for implementation are in process.