The effects of Alzheimer disease on driving-related abilities

Driving and Alzheimer's dementia or mild cognitive impairment: a systematic review of the existing guidelines emphasizing on the neurologist's role

BACKGROUND

Driving is a complex task requiring the integrity and the cooperation of cognition, motor, and somatosensory skills, all of which are impacted by neurological diseases.

OBJECTIVE

Identification of neurologist's role when assessing fitness to drive of cognitively impaired individuals.

METHODS

We performed a systematic review of the guidelines/recommendations (G/Rs) regarding the evaluation of driving fitness of patients with mild cognitive impairment (MCI) and/or dementia. Emphasis was put on the neurological and neuropsychological aspects of the evaluation.

RESULTS

Eighteen G/Rs were included in the review (9 national guidelines, 5 recommendation papers, 3 consensus statements, and 1 position paper). All G/Rs referred to drivers with dementia and 9/18 referred to drivers with MCI. A common approach among G/Rs is the initial trichotomization of patients in safe to drive, unsafe to drive, and undetermined cases, which are referred to a second-line evaluator. First-line evaluators are general practitioners in 10/18 G/Rs; second-line evaluators are neurologists in 7/18 G/Rs. Specific neuropsychological tests are proposed in 11/18 G/Rs and relative cut-off values in 7/18. The most commonly used tests are the MMSE, TMT, and CDT. A thorough neurological examination is proposed in only 1/18 G/R.

CONCLUSION

Although extensive multi-disciplinary research has provided useful information for driving behavior of cognitively impaired individuals, we are still far from a widely accepted approach of driving ability evaluation in this increasing population. A comprehensive assessment from a multi-disciplinary team in which the neurologist plays a critical role seems to be required, although this has not yet been implemented in any G/Rs.

General cognitive impairment as a risk factor for motor vehicle collision involvement: a prospective population-based study

This study examined whether cognitive impairment and decline as assessed by a brief mental status screening test is associated with future crash risk in a cohort of older drivers. A three-year prospective study was conducted in a population-based sample of 2000 licensed drivers, aged 70 years and older. At the baseline visit, cognitive impairment was defined as <24 on the Mini Mental State Exam (MMSE). Decline was defined as those with a one-year change in MMSE scores in the lowest quartile (largest decrease). Motor vehicle collision involvement was obtained from the Alabama Department of Public Safety. Poisson regression was used to calculate crude and adjusted rate ratios (RR). There were 278 crashes during the follow-up period. Rates of crash involvement were higher for those with cognitive impairment (crude RR = 2.33) compared to those without impairment at baseline; adjustment for potential confounders namely age and visual processing speed attenuated this relationship (adjusted RR = 1.26, 95% confidence interval (CI) 0.65–2.44). Drivers who experienced a pronounced decline in estimated MMSE scores in one year were 1.64 (95% CI 1.04–2.57) times more likely to have a future at-fault crash, as compared to those whose scores did not decline. Evaluation of MMSE over time may provide important insight in an older driver’s future risk of at-fault crash involvement.

Relationship between areas of cognitive functioning on the Mini-Mental State Examination and crash risk

Previous studies have suggested that the pattern of cognitive impairment in crash-involved older drivers is different from non-crash-involved older drivers. This study assessed the relationship between seven areas of cognitive functioning (orientation to time, orientation to place, registration, attention and calculation, recall, language, and visual construction) on the Mini-Mental State Examination (MMSE) collected at baseline and rates of future crash involvement in a prospective population-based sample of older drivers. Motor vehicle collision (MVC) involvement was obtained from the Alabama Department of Public Safety. Poisson regression was used to calculate crude and adjusted rate ratios (RR). Older drivers having difficulties in place orientation were more than 6 times (95% CI 1.90–19.86) more likely to be involved in a future crash (adjusted RR = 6.14, 95% confidence interval (CI) 1.90–19.86) and at-fault crash (adjusted RR = 6.39, 95% CI 1.51–27.10). Impairment in the other cognitive areas was not associated with higher rates of crash or at-fault crash involvement. The findings were validated in an independent sample of high-risk older drivers and a similar pattern of results was observed. Spatial orientation impairment can help identify older drivers who are more likely to crash in the future.

Is Mild Dementia Related to Unsafe Street-Crossing Decisions?

The overrepresentation of very old people (75 or older) in pedestrian crash statistics raises the issue of the effects of normal and pathologic ageing on gap-selection difficulties during street crossing. The present study focused on Alzheimer disease, a condition commonly associated with cognitive declines detrimental to daily life activities such as crossing the street. Twenty-five participants with mild dementia and 33 controls carried out a street-crossing task in a simulated environment. They also took a battery of cognitive tests. The mild-dementia group was more likely than the control group to make decisions that led to collisions with approaching cars, especially when the traffic was coming from 2 directions and they were in the far lane. Regression analyses demonstrated that the increased likelihood of collisions in the dementia group was associated with impairments in processing-speed and visual-attention abilities assessed on the Useful Field of View test. This test has already proven useful for predicting driving outcomes, falls, and street-crossing difficulties in healthy old adults, and among drivers with Alzheimer disease. Clinicians are encouraged to use it to help estimate whether a patient can drive, walk, and cross a street safely.

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.

Not if, but when: impact of a driving and dementia awareness and education campaign for primary care physicians

Background

Canadian physicians are responsible for assessing medical fitness to drive; however, national data indicate that physicians lack confidence in performing such assessments and face numerous barriers to addressing driving in patients with dementia. We report on the impact of a provincial Web-based resource (www.notifbutwhen.ca) regarding driving cessation in dementia aimed towards primary care physicians (PCPs).

Methods

A pre/post cross-sectional survey (n = 134 baseline and n = 113 follow-up) of English-speaking, Nova Scotian PCPs. Descriptive statistics, chi-square, Pearson correlation, and multivariable logistic regression (controlling for sex, years of practice, and practice type) are reported.

Results

Most PCPs consider discussions regarding driving cessation to be routine part of dementia care; however, report multiple barriers to such discussions. Although the Web-based resource and awareness campaign were not associated with improvement in physician comfort in assessing driving risk in dementia, after completion of the campaign, fewer PCPs reported avoiding the topic of driving. Additionally, family resistance and lack of resources were less often reported as barriers.

Conclusions

Despite a lack of confidence, Nova Scotian PCPs routinely discuss driving cessation, and perform driving assessments for individuals with dementia. The Web-based resource and awareness campaign have shown moderate effectiveness in addressing specific barriers to assessment (e.g., caregiver resistance, lack of resources). Future efforts will address additional barriers, such as lack of comfort in decision-making.

Driving assessment for maintaining mobility and safety in drivers with dementia

BACKGROUND

Demographic changes are leading to an increase in the number of older drivers: as dementia is an age-related disease, there is also an increase in the numbers of drivers with dementia. Dementia can impact on both the mobility and safety of drivers, and the impact of formal assessment of driving is unknown in terms of either mobility or safety. Those involved in assessment of older drivers need to be aware of the evidence of positive and negative effects of driving assessment. Cognitive tests are felt by some authors to have poor face and construct validity for assessing driving performance; extrapolating from values in one large-scale prospective cohort study, the cognitive test that most strongly predicted future crashes would, if used as a screening tool, potentially prevent six crashes per 1000 people over 65 years of age screened, but at the price of stopping the driving of 121 people who would not have had a crash.

PRIMARY OBJECTIVES

1. to assess whether driving assessment facilitates continued driving in people with dementia;2. to assess whether driving assessment reduces accidents in people with dementia.

SECONDARY OBJECTIVE

1. to assess the quality of research on assessment of drivers with dementia.

SEARCH METHODS

ALOIS, the Cochrane Dementia Group's Specialized Register was searched on 13 September 2012 using the terms: driving or driver* or "motor vehicle*" or "car accident*" or "traffic accident*" or automobile* or traffic. This register contains records from major healthcare databases, ongoing trial databases and grey literature sources and is updated regularly.

SELECTION CRITERIA

We sought randomised controlled trials prospectively evaluating drivers with dementia for outcomes such as transport mobility, driving cessation or motor vehicle accidents following driving assessment.

DATA COLLECTION AND ANALYSIS

Each review author retrieved studies and assessed for primary and secondary outcomes, study design and study quality.

MAIN RESULTS

No studies were found that met the inclusion criteria. A description and discussion of the driving literature relating to assessment of drivers with dementia relating to the primary objectives is presented.

AUTHORS' CONCLUSIONS

In an area with considerable public health impact for drivers with dementia and other road users, the available literature fails to demonstrate the benefit of driver assessment for either preserving transport mobility or reducing motor vehicle accidents. Driving legislation and recommendations from medical practitioners requires further research that addresses these outcomes in order to provide the best outcomes for both drivers with dementia and the general public.

Driving assessment for maintaining mobility and safety in drivers with dementia

BACKGROUND

Demographic changes are leading to an increase in the number of older drivers: as dementia is an age-related disease, there is also an increase in the numbers of drivers with dementia. Dementia can impact on both the mobility and safety of drivers, and the impact of formal assessment of driving is unknown in terms of either mobility or safety. Those involved in assessment of older drivers need to be aware of the evidence of positive and negative effects of driving assessment. Cognitive tests are felt by some authors to have poor face and construct validity for assessing driving performance; extrapolating from values in one large-scale prospective cohort study, the cognitive test that most strongly predicted future crashes would, if used as a screening tool, potentially prevent six crashes per 1000 people over 65 years of age screened, but at the price of stopping the driving of 121 people who would not have had a crash.

PRIMARY OBJECTIVES

1. to assess whether driving assessment facilitates continued driving in people with dementia; 2. to assess whether driving assessment reduces accidents in people with dementia.

SECONDARY OBJECTIVE

1. to assess the quality of research on assessment of drivers with dementia.

SEARCH METHODS

ALOIS, the Cochrane Dementia Group's Specialized Register was searched on 13 September 2012 using the terms: driving or driver* or "motor vehicle*" or "car accident*" or "traffic accident*" or automobile* or traffic. This register contains records from major healthcare databases, ongoing trial databases and grey literature sources and is updated regularly.

SELECTION CRITERIA

We sought randomised controlled trials prospectively evaluating drivers with dementia for outcomes such as transport mobility, driving cessation or motor vehicle accidents following driving assessment.

DATA COLLECTION AND ANALYSIS

Each review author retrieved studies and assessed for primary and secondary outcomes, study design and study quality.

MAIN RESULTS

No studies were found that met the inclusion criteria. A description and discussion of the driving literature relating to assessment of drivers with dementia relating to the primary objectives is presented.

AUTHORS' CONCLUSIONS

In an area with considerable public health impact for drivers with dementia and other road users, the available literature fails to demonstrate the benefit of driver assessment for either preserving transport mobility or reducing motor vehicle accidents. Driving legislation and recommendations from medical practitioners requires further research that addresses these outcomes in order to provide the best outcomes for both drivers with dementia and the general public.

Executive function and activities of daily living in Alzheimer's disease: a correlational meta-analysis

BACKGROUND

The assessment of executive function (EF) and activities of daily living (ADL) are important elements in the diagnosis of Alzheimer's disease.

METHODS

Following a comprehensive search in three databases, a random-effects meta-analysis was used to investigate the association between ADL ability and seventeen tests of EF, three tests of attention and working memory and the Mini-Mental State Examination. The association between EF and ADL ability was further investigated in relation to four different methods of assessing ADL, and one specific ADL, driving.

RESULTS

Forty-nine studies met the inclusion criteria, and a total of 3,663 participants were included, the majority of whom were diagnosed with Alzheimer's disease. Most of the individual tests, including commonly used tests of EF such as the Clock Drawing Test, Letter Fluency and the Trail Making Test Part B, showed a significant moderate association with ADL. Associations between EF and ADL ability were similar for all four methods of assessing ADL ability. Driving ability was also moderately associated with EF.

CONCLUSION

The meta-analysis suggests a consistent moderate association between ADL and EF, supporting the growing evidence for a link between ADL and executive dysfunction in early dementia.

The Addenbrooke's Cognitive Examination Revised as a potential screening test for elderly drivers

Considerable research has shown that neuropsychological tests are predictive of real-world driving ability. The Mini-Mental State Examination (MMSE) is a brief cognitive test that has been commonly used in the assessment of older drivers. However, this test has inherent problems that limit its validity to evaluate cognitive abilities related to driving and to screen for driving impairments in non-demented people. Therefore, it is useful to test new screening instruments that may predict potential unsafe drivers who require an in-depth neuropsychological assessment in a specialised centre. To date, the utility of the Addenbrooke's Cognitive Examination Revised (ACE-R) as an indicator of driving ability has not been established. In the current study, fifty older drivers (mean age=73.1 years) who were referred for a psychological assessment, the protocol of which included the ACE-R, underwent an on-road driving test. Using linear discriminant analyses, the results highlighted the higher classification accuracy of the ACE-R compared to the MMSE score, particularly for detecting unsafe drivers. Measures of visuospatial and executive functions, which are not incorporated in the MMSE score, had an incremental value in the prediction of driving ability. This emerging brief cognitive test may warrant additional study for use in the fitness to drive assessment of older adults.

Investigating the role of feedback and motivation in clinical reaction time assessment

OBJECTIVE

To investigate the influence of performance feedback and motivation during 2 tests of simple visuomotor reaction time (RT).

DESIGN

Cross-sectional, observational study.

SETTING

Outpatient academic physiatry clinic.

PARTICIPANTS

Thirty-one healthy adults (mean [SD], 54 ± 15 years).

METHODS

Participants completed a clinical test of RT (RT(clin)) and a computerized test of RT with and without performance feedback (RT(compFB) and RT(compNoFB), respectively) in randomly assigned order. They then ranked their degree of motivation during each test. RT(clin) measured the time required to catch a suspended vertical shaft by hand closure after release of the shaft by the examiner. RT(compFB) and RT(compNoFB) both measured the time required to press a computer key in response to a visual cue displayed on a computer monitor. Performance feedback (visual display of the previous trial and summary results) was provided for RT(compFB), but not for RT(compNoFB).

MAIN OUTCOME MEASUREMENTS

Means and standard deviations of RT(clin), RT(compFB), and RT(compNoFB) and participants' self-reported motivation on a 5-point Likert scale for each test.

RESULTS

There were significant differences in both the means and standard deviations of RT(clin), RT(compFB), and RT(compNoFB) (F(2,60) = 81.66, P < .0001; F(2,60) = 32.46, P < .0001, respectively), with RT(clin) being both the fastest and least variable of the RT measurements. RT(clin) was more strongly correlated with RT(compFB) (r = 0.449, P = .0011) than with RT(compNoFB) (r = 0.314, P = .086). The participants reported similar levels of motivation between RT(clin) and RT(compFB), both of which were reported to be more motivating than RT(compNoFB).

CONCLUSIONS

The stronger correlation between RT(clin) and RT(compFB) as well as the higher reported motivation during RT(clin) and RT(compFB) testing suggest that performance feedback is a positive motivating factor that is inherent to RT(clin) testing. RT(clin) is a simple, inexpensive technique for measuring RT and appears to be an intrinsically motivating task. This motivation may promote faster, more consistent RT performance compared with currently available computerized programs, which do not typically provide performance feedback.

Barriers to assessing fitness to drive in dementia in nova scotia: informing strategies for knowledge translation

Background and Purpose

Over half a million Canadians have a diagnosis of dementia, approximately 25–30% of whom continue to drive. Individuals with dementia have a risk of motor vehicle collision up to eight times that of drivers without dementia. In Nova Scotia, the responsibility of reporting unsafe drivers is discretionary, but national survey data indicate that many physicians do not feel comfortable assessing driving safety. We report on barriers to addressing driving safety as identified by Nova Scotian primary care physicians (PCPs).

Methods

We conducted a cross-sectional study of surveys completed by 134 English-speaking, Nova Scotian PCPs (mean years of practice 17.9±11; 53% female; 58% urban). Statistical analysis included descriptive statistics and multivariate linear and logistic regression (controlling for sex, urban/rural, and years of practice).

Results

Most PCPs (96%) routinely address driving safety in dementia, but physicians at all levels of experience find these discussions uncomfortable and sometimes avoid them. PCPs experience multiple barriers to assessing driving in dementia and desire further education and resources.

Conclusions

In Nova Scotia, driving assessment is considered part of routine care in dementia, but general lack of comfort in administering these assessments is a risk. To improve physician comfort further education and resources are required.

Older drivers' road traffic crashes in the UK

A sample of over 2000 crashes involving drivers aged 60 years or over was considered, from three UK midland police forces, from the years 1994-2007 inclusive. Each case was summarized on a database including the main objective features (such as time and place), a summary narrative, a sketch plan and a list of explanatory factors. The main findings were that older drivers have significant problems with intersection collisions and failing to give right of way; these formed the largest single class of crashes in the sample. Possible behavioural explanations for this will be discussed, along with other findings regarding older driver blameworthiness, fatigue and illness, time of day factors, and 'unintended accelerations'.

Practice parameter update: evaluation and management of driving risk in dementia: report of the Quality Standards Subcommittee of the American Academy of Neurology

OBJECTIVE

To review the evidence regarding the usefulness of patient demographic characteristics, driving history, and cognitive testing in predicting driving capability among patients with dementia and to determine the efficacy of driving risk reduction strategies.

METHODS

Systematic review of the literature using the American Academy of Neurology's evidence-based methods.

RECOMMENDATIONS

For patients with dementia, consider the following characteristics useful for identifying patients at increased risk for unsafe driving: the Clinical Dementia Rating scale (Level A), a caregiver's rating of a patient's driving ability as marginal or unsafe (Level B), a history of crashes or traffic citations (Level C), reduced driving mileage or self-reported situational avoidance (Level C), Mini-Mental State Examination scores of 24 or less (Level C), and aggressive or impulsive personality characteristics (Level C). Consider the following characteristics not useful for identifying patients at increased risk for unsafe driving: a patient's self-rating of safe driving ability (Level A) and lack of situational avoidance (Level C). There is insufficient evidence to support or refute the benefit of neuropsychological testing, after controlling for the presence and severity of dementia, or interventional strategies for drivers with dementia (Level U).

Anxiety of Alzheimer's disease patients before and after a standardized on-road driving test

BACKGROUND

A large number of licensed elderly drivers are demented or are likely to become demented. On-road driving tests, a method often used to assess driver competency, are likely anxiety-provoking for elderly individuals. This article examines the relationship between anxiety and driving performance in a mildly demented and elderly control (EC) sample.

METHODS

Anxiety ratings of fear and tension, as assessed by visual analog scales, of 84 patients clinically diagnosed with mild Alzheimer's disease (AD) (68 safe/marginal and 16 unsafe drivers) were compared with those of 44 age- and education-equated safe/marginal EC participants, both before and after a standardized on-road driving test.

RESULTS

Analyses revealed significant positive correlations between AD patients' pre-road test and post-road test tension and post-road test fear ratings and total road test score. Subsequent analyses of variance showed no significant pre-road test differences in fear ratings between the three groups but significantly higher levels of tension among the unsafe AD participants. After adjusting for baseline group differences, unsafe AD drivers experienced stable or higher anxiety levels after road test, whereas both the EC and safe/marginal AD drivers endorsed a significant reduction in anxiety.

DISCUSSION

Unlike their safe EC and safe AD driver counterparts, unsafe AD patients reported continued elevated levels of fear and tension after the road test. Given these findings, we suggest that the most appropriate time for driving instructors to counsel patients regarding their driving skills might be directly after the road test.

Cognitive predictors of unsafe driving in older drivers: a meta-analysis

BACKGROUND

Older drivers are at a higher risk of being involved in a motor vehicle accident. However, on-road assessments of all older drivers are impractical, highlighting the need to screen for potentially unsafe drivers. This study undertook a meta-analysis of research examining the cognitive predictors of driving ability in older drivers in order to provide an evidence-based method for screening drivers.

METHODS

Comprehensive searches were undertaken of the PubMed, PsycINFO, CINAHL, and Health-Source Nursing electronic databases between 1980 and 2007 in order to identify studies that examined cognitive differences between drivers aged over 55 years who either passed or failed a driving assessment. Twenty-one studies were eligible for inclusion. Weighted Cohen's d effect sizes, percentage overlap statistics, Fail-safe Ns and 95% CIs were calculated for all cognitive tests.

RESULTS

The best predictors of on-road driving were the Ergovision and Useful Field of View (UFOV) tests, a complex RT task, Paper Folding task, Dot Counting, WMS Visual Reproduction, and Computerized Visual Attention Task. Simulator driving performance was best predicted by the Benton Line Orientation Task, Clock Drawing, a Driver Scanning task, the UFOV, WAIS Picture Arrangement and MMSE. Finally, the Trail Making Test, Stroop, UFOV, WAIS Block Design, and Automated Psychophysical Test were good predictors of driving problems.

CONCLUSIONS

There are a variety of tests that appear suitable for screening older drivers, the exact choice of which depends on the "gold standard" for determining driving ability (on-road driving, driving simulator, driving problems) and whether a computerized or paper-and-pencil task is required.

Driving assessment for maintaining mobility and safety in drivers with dementia

BACKGROUND

Demographic changes are leading to an increase in the number of older drivers: as dementia is an age-related disease, there is also an increase in the numbers of drivers with dementia. Dementia can impact on both the mobility and safety of drivers, and the impact of formal assessment of driving is unknown in terms of either mobility or safety. Those involved in assessment of older drivers need to be aware of the evidence of positive and negative effects of driving assessment. Although cognitive tests are felt by some authors to have poor face and construct validity for assessing driving performance, extrapolating from values in one large-scale prospective cohort study, the cognitive test that most strongly predicted future crashes would, if used as a screening tool, potentially prevent six crashes per 1000 people over 65 screened, but at the price of stopping the driving of 121 people who would not have had a crash.

PRIMARY OBJECTIVES

1. To assess whether driving assessment facilitates continued driving in people with dementia 2. To assess whether driving assessment reduces accidents in people with dementia.

SECONDARY OBJECTIVE

To assess the quality of research on assessment of drivers with dementia.

SEARCH STRATEGY

The Cochrane Dementia Group's Specialized Register was searched on 30 October 2007 using the terms: driving or driver* or "motor vehicle*" or "car accident*" or "traffic accident*" or automobile* or traffic. This register contains records from major healthcare databases, ongoing trial databases and grey literature sources and is updated regularly.

SELECTION CRITERIA

We sought randomized controlled trials prospectively evaluating drivers with dementia for outcomes such as transport mobility, driving cessation or motor vehicle accidents following driving assessment.

DATA COLLECTION AND ANALYSIS

Each author retrieved studies and assessed for primary and secondary outcomes, study design and study quality.

MAIN RESULTS

No studies were found that met the inclusion criteria. A description and discussion of the driving literature relating to assessment of drivers with dementia relating to the primary objectives is presented.

AUTHORS' CONCLUSIONS

In an area with considerable public health impact for drivers with dementia and other road users, the available literature fails to demonstrate the benefit of driver assessment for either preserving transport mobility or reducing motor vehicle accidents. Driving legislation and recommendations from medical practitioners requires further research that addresses these outcomes in order to provide the best outcomes for both drivers with dementia and the general public.

Computerized maze navigation and on-road performance by drivers with dementia

This study examined the ability of computerized maze test performance to predict the road test performance of cognitively impaired and normal older drivers. The authors examined 133 older drivers, including 65 with probable Alzheimer disease, 23 with possible Alzheimer disease, and 45 control subjects without cognitive impairment. Subjects completed 5 computerized maze tasks employing a touch screen and pointer as well as a battery of standard neuropsychological tests. Parameters measured for mazes included errors, planning time, drawing time, and total time. Within 2 weeks, subjects were examined by a professional driving instructor on a standardized road test modeled after the Washington University Road Test. Road test total score was significantly correlated with total time across the 5 mazes. This maze score was significant for both Alzheimer disease subjects and control subjects. One maze in particular, requiring less than 2 minutes to complete, was highly correlated with driving performance. For the standard neuropsychological tests, highest correlations were seen with Trail Making A (TrailsA) and the Hopkins Verbal Learning Tests Trial 1 (HVLT1). Multiple regression models for road test score using stepwise subtraction of maze and neuropsychological test variables revealed significant independent contributions for total maze time, HVLT1, and TrailsA for the entire group; total maze time and HVLT1 for Alzheimer disease subjects; and TrailsA for normal subjects. As a visual analog of driving, a brief computerized test of maze navigation time compares well to standard neuropsychological tests of psychomotor speed, scanning, attention, and working memory as a predictor of driving performance by persons with early Alzheimer disease and normal elders. Measurement of maze task performance appears to be useful in the assessment of older drivers at risk for hazardous driving.

A longitudinal study of drivers with Alzheimer disease

OBJECTIVE

The goal of this study was to define the natural progression of driving impairment in persons who initially have very mild to mild dementia.

METHODS

We studied 128 older drivers, including 84 with early Alzheimer disease (AD) and 44 age-matched control subjects without cognitive impairment. Subjects underwent repeated assessments of their cognitive, neurologic, visual, and physical function over 3 years. Self-reports of driving accidents and traffic violations were supplemented by reports from family informants and state records. Within 2 weeks of the office evaluation, subjects were examined by a professional driving instructor on a standardized road test.

RESULTS

At baseline, subjects with AD had experienced more accidents and performed more poorly on the road test, compared to controls. Over time, both groups declined in driving performance on the road test, with subjects with AD declining more than controls. Survival analysis indicated that while the majority of subjects with AD passed the examination at baseline, greater severity of dementia, increased age, and lower education were associated with higher rates of failure and marginal performance.

CONCLUSIONS

This study confirms previous reports of potentially hazardous driving in persons with early Alzheimer disease, but also indicates that some individuals with very mild dementia can continue to drive safely for extended periods of time. Regular follow-up assessments, however, are warranted in those individuals.

Medical management of frontotemporal dementia

There are no Food and Drug Administration (FDA)-approved medications for the medical management of frontotemporal dementia and its related disorders, so all management recommendations are necessarily off-label and borrowed from experience with Alzheimer's disease, psychiatric disease, and related medical illnesses. Six areas of pharmacotherapeutic consideration are prevention (primary and secondary), intellectual decline, behavioral disorders (such as depression, anxiety, and psychosis), sleep disorders, frequently associated disorders (including motor neuron disease), and abrupt decline. In addition to pharmacotherapy, important lifestyle issues confronting the clinician include driving cessation, securing any weapons maintained at home, assisted living, and caregiver burnout.

Systematic Review of Driving Risk and the Efficacy of Compensatory Strategies in Persons with Dementia

OBJECTIVES

To determine whether persons with dementia are at greater driving risk and, if so, to estimate the magnitude of this risk and determine whether there are efficacious methods to compensate for or accommodate it.

DESIGN

Systematic review of the literature.

SETTING

Case-control studies.

PARTICIPANTS

Drivers with a diagnosis of dementia.

MEASUREMENTS

Most studies used state and caregiver reported crash rates, performance-based road tests, and driving simulator evaluations as their outcome measures.

RESULTS

Twenty-three studies were included. Drivers with dementia universally exhibited poorer performance on road tests and simulator evaluations, although only one study using an objective measure of motor vehicle crashes was able to show that drivers with dementia were involved in more crashes than control subjects. No studies were found that examined the efficacy of methods to compensate for or accommodate their worse driving performance.

CONCLUSION

Drivers with dementia are poorer drivers than cognitively normal drivers, but studies have not consistently demonstrated higher crash rates. Clinicians and policy makers must take these findings into account when addressing issues pertinent to drivers with a diagnosis of dementia.

Driving abilities in frontotemporal dementia patients

OBJECTIVE

To evaluate driving competency and the relationship between neuropsychiatric symptoms and driving behavior in frontotemporal dementia (FTD) patients.

METHODS

Fifteen patients with a diagnosis of FTD and 15 healthy controls were administered a driving simulation task. Measures of driving performance and neuropsychiatric symptoms were assessed.

RESULTS

The FTD patients received more speeding tickets, ran more stop signs and were involved in more off-road crashes and collisions than the controls. The patients' overall average speed was significantly higher. Driving performance was correlated with agitated behavior.

CONCLUSIONS

Behavioral changes characteristic of FTD patients have an impact on their driving skills leading to inappropriate driving behavior.

Clinical Utility of Office-Based Cognitive Predictors of Fitness to Drive in Persons with Dementia: A Systematic Review

OBJECTIVES

To perform a systematic review of evidence available regarding in-office cognitive tests that differentiate safe from unsafe drivers with dementia.

DESIGN

A comprehensive literature search of multiple databases including Medline, CINAHL, PsychInfo, AARP Ageline, and Sociofile from 1984 to 2005 was performed. This was supplemented by a search of Current Contents and a review of the bibliographies of all relevant articles.

SETTING

English prospective cohort, retrospective cohort, and case-control studies that used accepted diagnostic criteria for dementia or Alzheimer's disease and that employed one of the primary outcomes of crash, simulator assessment, or on-road assessment were included.

PARTICIPANTS

Two reviewers.

MEASUREMENTS

The reviewers independently assessed study design, main outcome of interest, cognitive tests, and population details and assigned a Newcastle-Ottawa quality assessment rating.

RESULTS

Sixteen articles met the inclusion criteria. Tests recommended by guidelines (e.g., the American Medical Association (AMA) and Canadian Medical Association guidelines) for the assessment of fitness to drive did not demonstrate robustly positive findings (e.g., Mini-Mental State Examination, Trails B) or were not evaluated in any of the included studies (e.g., Clock Drawing). Fifteen studies did not report any cutoff scores.

CONCLUSION

Without validated cutoff scores, it is impossible to employ tests in a standardized fashion in front-line clinical settings. This study identified a research gap that will prevent the development of evidence-based guidelines. Recommendations to address this gap are that driving researchers routinely perform cutoff score analyses and that stakeholder organizations (e.g., AMA, American Geriatrics Society) sponsor consensus fora to review driving research methodologies.

Dementia and driving: autonomy versus safety

PURPOSE

This article reviews the effects of various types of dementia on driving skills, the available assessment measures, legal considerations, and the important role played by the nurse practitioner (NP) in the process of recommending driving cessation. It provides strategies and resources that may offer guidance to NPs who are attempting to balance the continued independence of patients with dementia, as represented by driving, with the safety not only of such patients but also of the public at large.

DATA SOURCES

A review of the biomedical literature, resources available on the World Wide Web, and illustrative case studies were used.

CONCLUSIONS

The diagnosis of dementia alone is often insufficient to determine driver competence because the topographic losses of dementia are complex. Recognizing when cessation should occur is made more difficult because objective assessment tools do not exist to predict impaired driving skills. Recommending driving cessation at the appropriate time can be a challenge for NPs, who must balance such a significant impact on the driver's autonomy with concerns about public safety if the patient continues to drive despite progressive impairment.

IMPLICATIONS FOR PRACTICE

The progressive loss of cognitive abilities in dementia presents a series of ongoing challenges for the patient throughout the disease continuum. Unfortunately, the recommendation to stop driving can present one of the more immediate issues confronting the patient, the family, and the healthcare provider. Failure to assess diminished driving skill can lead either to premature or to delayed driving cessation. Either outcome can have adverse effects on the patient, the patient's family, and public safety.

Driving scenes test of the Neuropsychological Assessment Battery (NAB) and on-road driving performance in aging and very mild dementia

The Driving Scenes test of the new Neuropsychological Assessment Battery (NAB; [Stern, R.A., & White, T. (2003a). Neuropsychological Assessment Battery. Lutz, FL: Psychological Assessment Resources, Inc.]) measures several aspects of visual attention thought to be important for driving ability. The current study examined the relationship between scores on the Driving Scenes test and on-road driving performance on a standardized driving test. Healthy participants performed significantly better on the Driving Scenes test than did very mildly demented participants. A correlation of 0.55 was found between the brief, office-based Driving Scenes test and the 108-point on-road driving score. Furthermore, the Driving Scenes test scores differed significantly across the driving instructor's three global ratings (safe, marginal, and unsafe), and results of a discriminant function analysis indicated that the Driving Scenes test correctly classified 66% of participants into these groups. Thus, the new NAB Driving Scenes test appears to have good ecological validity for real-world driving ability in normal and very mildly demented older adults.

The older driver with dementia: an updated literature review

INTRODUCTION

At some point during their illness, drivers with dementia pose a public safety risk.

METHOD

To address the issue of determining driving competence in drivers with dementia, the authors reviewed 11 studies.

RESULTS

When comparing different driving assessments, the authors found that while road tests, simulators, and neuropsychological tests are important, each has limitations.

CONCLUSION

Neuropsychological tests that highlighted visual spatial skills, attention, and reaction time provided the most meaningful correlations with driving performance. Furthermore, the authors recommend that patients with MMSE scores of 24 or less have a driving evaluation, and that driving evaluations be repeated at six month intervals or more frequently if a noticeable decline is observed.

IMPACT

Because many older adults with dementia continue to drive, competence must be addressed.

Driving and dementia: a review of the literature

The purpose of this article is to review the literature on the ability of individuals with dementia to drive an automobile. Based on a review of the literature, several factors were identified that may be useful in differentiating between people with dementia who presently remain safe drivers from those who have progressed to impaired driving. These factors include disease duration and severity, sex, patient self-assessment, family assessment, neuropsychological measures, findings on road evaluations, and driving simulator testing. The approach of the physician to driving and dementia is addressed, including in-office screening, referral for on-road driving assessments, and the potential for physician reporting to state agencies.

Alcohol intoxication effects on visual perception: an fMRI study

We examined the effects of two doses of alcohol (EtOH) on functional magnetic resonance imaging (fMRI) activation during a visual perception task. The Motor-Free Visual Perception Test-Revised (MVPT-R) provides measures of overall visual perceptual processing ability. It incorporates different cognitive elements including visual discrimination, spatial relationships, and mental rotation. We used the MVPT-R to study brain activation patterns in healthy controls (1) sober, and (2) at two doses of alcohol intoxication with event-related fMRI. The fMRI data were analyzed using a general linear model approach based upon a model of the time course and a hemodynamic response estimate. Additionally, a correlation analysis was performed to examine dose-dependent amplitude changes. With regard to alcohol-free task-related brain activation, we replicate our previous finding in which SPM group analysis revealed robust activation in visual and visual association areas, frontal eye field (FEF)/dorsolateral prefrontal cortex (DLPFC), and the supplemental motor area (SMA). Consistent with a previous study of EtOH and visual stimulation, EtOH resulted in a dose-dependent decrease in activation amplitude over much of the visual perception network and in a decrease in the maximum contrast-to-noise ratio (in the lingual gyrus). Despite only modest behavior changes (in the expected direction), significant dose-dependent activation increases were observed in insula, DLPFC, and precentral regions, whereas dose-dependent activation decreases were observed in anterior and posterior cingulate, precuneus, and middle frontal areas. Some areas (FEF/DLPFC/SMA) became more diffusely activated (i.e., increased in spatial extent) at the higher dose. Alcohol, thus, appears to have both global and local effects upon the neural correlates of the MVPT-R task, some of which are dose dependent.

The Relationship Between Neuropsychological Functioning and Driving Ability in Dementia: A Meta-Analysis

A meta-analysis of 27 primary studies was conducted to examine the relationship between neuropsychological functioning and driving ability for adults with dementia. When studies using a control group were included, the relationship between cognitive measures and on-road or non-road driving measures was significant for all reported domains; mean correlations ranged from.35 to.65. Caregiver reports of driving ability and cognitive variables were correlated significantly only on measures of mental status and visuospatial skills. When studies using a control group were excluded, moderate mean correlations were observed for visuospatial skills and on-road or non-road measures, and for mental status with non-road tests. Other effects were small or nonsignificant. Implications for basing driving recommendations on neuropsychological testing are discussed.

The role of physicians in assessing older drivers: barriers, opportunities, and strategies

BACKGROUND

Evaluation of the older driver is a difficult task for primary care physicians. We investigated the physician-perceived barriers to assessing older drivers in primary care practice.

METHODS

Twenty family physicians whose patients had completed a clinical questionnaire and neuropsychological tests participated in one of 2 focus groups. Physicians were asked about barriers to assessing older drivers in primary care and the usefulness of neuropsychological tests for assessing driving ability.

RESULTS

A number of themes emerged related to barriers in the assessment of the older driver. Major themes included concerns about being liable for the results of driving related screening and about patients reacting unfavorably to a driving assessment including cognitive tests. Physicians uniformly agreed that a protocol to guide driving assessment would be useful.

CONCLUSIONS

Physicians encounter a number of barriers to assessing older drivers but recognize the importance of driving within the context of geriatric functional assessment.

Identifying driving impairment in Alzheimer disease: a comparison of self and observer reports versus driving evaluation

This study examined the relationship between driving behaviors and awareness of deficit in patients with Alzheimer's disease (AD). Fifteen mildly impaired AD patients and 15 healthy elderly controls with valid drivers' licenses were administered a series of questionnaires concerning daily functioning and driving performance, and all 30 subjects were evaluated on a standardized road test. Self-report and caregiver/informant responses were compared with determine levels of discrepancy in ratings, while comparisons of AD and healthy elderly controls revealed group differences. Actual driving performance was considered the standard by which to determine accuracy of perceptions. Drivers with AD were rated as significantly worse than healthy elderly drivers on nine of 10 driving behaviors by an independent evaluator. AD patients' self-reports of driving ability were significantly better than the evaluator's ratings on seven of the 10 items, whereas the healthy elderly drivers rated themselves better than did the evaluator on one item. Although caregivers were likely to acknowledge a general concern with their AD patients' driving, they underreported specific driving problems when their ratings were compared with those of an independent evaluator. These findings have implications for the development of caregiver-based modifications of driving behavior.

The effects of driving cessation on the elderly with dementia and their caregivers

This research explores how the loss of driving privileges by impaired drivers affects households. The particular focus is on the travel behavior and preceptions of people living in households where an elderly driver has had his or her license revoked due to Alzheimer's disease or a related dementia. The data for this analysis were drawn from a 1996 survey of households in California which queried the caregivers of people with dementia on how the former drivers access necessary destinations once they can no longer drive, and on the difficulties faced by other household members in seeking alternative means of transportation. After losing their license, the vast majority of people surveyed depended on informal support systems for transportation, such as rides from family and friends. Although such arrangements were not reported to be a problem for the majority of households, certain groups of non-drivers reported difficulty accessing services, particularly social and recreational destinations. The most commonly reported problem was a lack of available licensed drivers to chauffeur non-drivers. Importantly, no increase was observed in the number of people walking, using public transit, taxis, or van services following license revocation. People who did not live with at least one licensed driver and those who were younger and healthier reported the greatest mismatch between their need and desire to travel and the availability of transportation. In addition, some caregivers reported that they frequently missed work or stopped working entirely in order to care for and chauffeur people in the former drivers' household. Overall, these findings reinforce the importance of both developing transportation policies to support the functioning of informal transportation structures and in improving the range of alternative transportation options for those individuals with particular disabilities--like dementia--who are not well served by either informal arrangements or by formal transportation services for the disabled.

A single-photon emission computed tomography imaging study of driving impairment in patients with Alzheimer's disease

Single-photon emission computed tomography (SPECT) was used in this study to examine the neurophysiologic basis of driving impairment in 79 subjects with dementia. Driving impairment, as measured by caregiver ratings, was significantly related to regional reduction of right hemisphere cortical perfusion on SPECT, particularly in the temporo-occipital area. With increased severity of driving impairment, frontal cortical perfusion was also reduced. Clock drawing was more significantly related to driving impairment than the Mini-Mental State Examination (MMSE). Driving impairment in Alzheimer's disease is related to changes in cortical function which vary according to the severity of the disease. Cognitive tests of visuoperceptual and executive functions may be more useful screening tools for identifying those at greatest risk for driving problems than examinations like the MMSE that are weighted toward left-hemisphere-based verbal tasks.

Driving is more than pedal pushing

The purpose of this study was to determine the usefulness of neuropsychological assessment for predicting driving competency (as opposed to driving skill). Participants were divided into 2 groups, currently driving and not currently driving, based on patient and family member reports of driving ability. In addition, driving participants were only included if there had been no accidents or driving-related injuries in the past year. Stepwise discriminant function analysis was utilized to identify measures that were predictive but not redundant, thereby resulting in a shortened battery. The discriminant function analysis was able to correctly classify 94.4% of the overall sample. A factor analysis was used to identify the constructs that comprised the final short battery. In conclusion, this study demonstrated that a short neuropsychological battery was able to identify individuals who were competent to drive and those who were not competent to drive.

Determining the cause of memory loss in the elderly. From in-office screening to neuropsychological referral

Improved understanding of neurobehavior in normal aging, Alzheimer's disease, and late-life depression makes early detection of neurodegenerative conditions possible. Primary care physicians can screen patients' mental status and mood states with simple in-office tests. When screening results or the clinical picture is ambiguous or complex, neuropsychological evaluation is useful in making an early, reliable differentiation between dementia and normal aging. Early identification of neurologic problems provides an opportunity to enhance quality of life and long-term care. Medical interventions, such as a trial of donepezil hydrochloride (Aricept) or other memory-enhancing medications as they become available, can be started when results are likely to be optimal. Common coexisting problems (e.g., depression, falls) can be sought and managed. Additional important medical decisions (e.g., elective surgeries) may be considered differently when dementia is diagnosed early.

Automobile driving in Huntington's disease

We assessed the influence of the neurological and cognitive impairments of Huntington's disease (HD) on automobile driving. In a group of 73 HD outpatients, 53 (72%) continued to drive after illness onset. Those no longer driving had more severe symptoms than those still driving. Twenty-nine HD patients who were still driving and 16 healthy control subjects underwent a clinical examination, a cognitive examination, a driving-simulator assessment, and completed questionnaires about driving history and habits. HD patients performed significantly worse than control subjects on the driving-simulator tasks and were more likely to have been involved in a collision in the preceding 2 years (58% of HD vs. 11% of control subjects). Patients with collisions were less functionally impaired but had slower simple reaction time scores than did those without collisions. HD patients are at increased risk for accidents, but patients who have accidents are not easily distinguished from those who do not.

Changes in visual fixation and saccadic eye movements in Alzheimer's disease

Visual fixation and saccadic eye movements were assessed in 31 mild to moderately demented patients with probable Alzheimer's disease (AD) and 31 age- and education-matched nondemented elderly control subjects. Seventeen AD and 17 matched control subjects were reassessed after a 9-month interval. On a fixation task, duration of fixation and number of intrusive saccades were not different between groups at baseline or follow-up. Both AD patients and control subjects showed more intrusive saccades at follow-up than at baseline. AD patients showed increased latency to initiation of saccades at baseline and on follow-up. Amplitude and velocity of saccades were not different between groups at any visit. Changes in measures of fixation, but no saccade measure, correlated with changes in MMSE scores over testing sessions. These data suggest that fixation is more sensitive than are saccades to the progession of AD.