The MMSE should not be the sole indicator of fitness to drive in mild Alzheimer's dementia

Since Alzheimer’s disease may affect driving performance, patients with Alzheimer’s disease are assessed on fitness to drive. On-road driving assessments are widely used, and attempts have also been made to develop strategies to assess fitness to drive in a clinical setting. Preferably, a first indication of fitness to drive is obtained quickly after diagnosis using a single test such as the Mini-Mental State Examination (MMSE). The aim of this study is to investigate whether the MMSE can be used to predict whether patients with Alzheimer’s disease will pass or fail an on-road driving assessment. Patients with Alzheimer’s disease (n = 81) participated in a comprehensive fitness-to-drive assessment which included the MMSE as well as an on-road driving assessment [PLoS One 11(2):e0149566, 2016]. MMSE cutoffs were applied as suggested by Versijpt and colleagues [Acta Neurol Belg 117(4):811–819, 2017]. All patients with Alzheimer’s disease who scored below the lower cutoff (MMSE ≤ 19) failed the on-road driving assessment. However, a third of the patients with Alzheimer’s disease who scored above the upper cutoff (MMSE ≥ 25) failed the on-road driving assessment as well. We conclude that the MMSE alone has insufficient predictive value to correctly identify fitness to drive in patients with very mild-to-mild Alzheimer’s disease implicating the need for comprehensive assessments to determine fitness to drive in a clinical setting

How to investigate fitness to drive in patients with Alzheimer’s dementia

Background: In early stages of dementia, some patients are still fit to drive, but others are not. Patients and their family members seek for advice from their physicians. The gold standard to determine fitness to drive is a test ride on the road, but it remains difficult to decide which patients should be advised to do such a time and effort demanding on-road driving assessment and which not, as sensitive alternative instruments are lacking. Objective: The goal of this study is to develop a validated off-road fitness-to-drive test battery for older drivers with dementia. Methods: Patients with Alzheimer’s disease (n=100) performed a fitness-to-drive test battery consisting of interviews with the patient and an informant, various neuropsychological tests and rides in a driving simulator. All participants also completed a test ride on the road. Results: The validity of the off-road fitness-to-drive test battery was examined, in particular regarding its accuracy in predicting on-road driving performance. With information from the interviews only, 72,3% of the patients were classified correctly as fit or unfit to drive. When using neuropsychological tests or driving simulator rides, respectively 81,6% and 78,9% of the patients were classified correctly. A combination of the predictions based on the interviews, neuropsychological tests and driving simulator rides resulted in a correct classification in 88,5% of the cases. Conclusion: Interviews with patients with dementia and their informants have predictive value for fitness to drive. Neuropsychological tests and driving simulator rides both improve the accuracy of the prediction significantly. Three tests of the test battery were most predictive: tests for motor speed, hazard perception, and traffic theory knowledge. The test battery will serve both patients affected as well as those involved in the decision making process

How to investigate fitness to drive in patients with Alzheimer’s dementia

Background:In early stages of dementia, some patients are still fit to drive, but others are not. Patients and their family members seek for advice from their physicians. The gold standard to determine fitness to drive is a test ride on the road, but it remains difficult to decide which patients should be advised to do such a time and effort demanding on-road driving assessment and which not, as sensitive alternative instruments are lacking.Objective:The goal of this study is to develop a validated off-road fitness-to-drive test battery for older drivers with dementia.Methods:Patients with Alzheimer’s disease (n=100) performed a fitness-to-drive test battery consisting of interviews with the patient and an informant, various neuropsychological tests and rides in a driving simulator. All participants also completed a test ride on the road.Results:The validity of the off-road fitness-to-drive test battery was examined, in particular regarding its accuracy in predicting on-road driving performance. With information from the interviews only, 72,3% of the patients were classified correctly as fit or unfit to drive. When using neuropsychological tests or driving simulator rides, respectively 81,6% and 78,9% of the patients were classified correctly. A combination of the predictions based on the interviews, neuropsychological tests and driving simulator rides resulted in a correct classification in 88,5% of the cases.Conclusion:Interviews with patients with dementia and their informants have predictive value for fitness to drive. Neuropsychological tests and driving simulator rides both improve the accuracy of the prediction significantly. Three tests of the test battery were most predictive: tests for motor speed, hazard perception, and traffic theory knowledge. The test battery will serve both patients affected as well as those involved in the decision making process

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. (Author/publisher

Driving difficulties among patients with Alzheimer’s disease and other neurodegenerative disorders.

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. 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 showed that 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. The researchers concluded that 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. (Author/publisher

Assessing fitness to drive : a validation study on patients with mild cognitive impairment.

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). Eighteen patients with mild cognitive impairment completed the proposed approach to themeasurement of fitness to drive, including clinical interviews, a neuropsychological assessment, and driving simulator rides. The criterion fitness to drive was again assessed bymeans 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 showed that 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. The authors concluded that 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. (Author/publisher