Maze test performance and reported driving ability in early dementia

Driving Assessment for Persons with Dementia: How and when?

Dementia is a progressive neurodegenerative disease leading to deterioration in cognitive and physical skills. Driving is an important instrumental activity of daily living, essential for independence. However, this is a complex skill. A moving vehicle can be a dangerous tool in the hand of someone who cannot maneuver it properly. As a result, the assessment of driving capacity should be part of the management of dementia. Moreover, dementia comprises of different etiologies and stages consisting of different presentations. As a result, this study aims to identify driving behaviors common in dementia and compare different assessment methods. A literature search was conducted using the PRISMA checklist as a framework. A total of forty-four observational studies and four meta-analyses were identified. Study characteristics varied greatly with regards to methodology, population, assessments, and outcome measures used. Drivers with dementia performed generally worse than cognitively normal drivers. Poor speed maintenance, lane maintenance, difficulty managing intersections and poor response to traffic stimuli were the most common behaviors in drivers with dementia. Naturalistic driving, standardized road assessments, neuropsychological tests, participant self-rating and caregiver rating were the most common driving assessment methods used. Naturalistic driving and on-road assessments had the highest predictive accuracy. Results on other forms of assessments varied greatly. Both driving behaviors and assessments were influenced by different stages and etiologies of dementia at varying degrees. Methodology and results in available research are varied and inconsistent. As a result, better quality research is required in this field.

Visual disorders and driving ability in persons with dementia: A mini review

Background

Impaired driving ability in patients with Alzheimer’s disease (AD) is associated with a decline in cognitive processes and a deterioration of their basic sensory visual functions. Although a variety of ocular abnormalities have been described in patients with AD, little is known about the impact of those visual disorders on their driving performance.

Aim

Aim of this mini-review is to provide an update on the driving ability of patients with dementia and summarize the primary visual disorders affecting their driving behavior.

Methods

Databases were screened for studies investigating dementia, associated visual abnormalities and driving ability.

Results

There is consistent evidence that dementia affects driving ability. Patients with dementia present with a variety of visual disorders, such as visual acuity reduction, visual field defects, impaired contrast sensitivity, decline in color vision and age-related pathological changes, that may have a negative impact on their driving ability. However, there is a paucity in studies describing the impact of oculovisual decline on the driving ability of AD subjects. A bidirectional association between cognitive and visual impairment (VI) has been described.

Conclusion

Given the bidirectional association between VI and dementia, vision screening and cognitive assessment of the older driver should aim to identify at-risk individuals and employ timely strategies for treatment of both cognitive and ocular problems. Future studies should characterize the basic visual sensory status of AD patients participating in driving studies, and investigate the impact of vision abnormalities on their driving performance.

Driving Ability Evaluation and Rehabilitation for People With Alzheimer's Disease and Related Dementias

Worldwide, it is estimated that around 50 million older adults have Alzheimer's disease and related dementias (ADRD). Cognitive deficits associated with ADRD may affect a driver's perception and decision-making and potentially cause safety concerns. Despite much research, there lacks a comprehensive cognitive evaluation to determine the driving capability of a person with ADRD and it is unclear what are the most effective training and interventions that help to enhance driving performance for these individuals. The purpose of this article is to conduct a comprehensive literature survey to review and summarize studies of driving performance evaluation and intervention for people with ADRD and discuss perspectives for future studies. Although many studies have investigated the correlations between driving behaviors and cognitive performances for people with ADRD, it remains unclear how driving behaviors and cognitive performances are associated with psychophysiological measures. We discussed the need to develop regular driving evaluation and rehabilitation protocol for people with ADRD. We also highlighted the potential benefit to combine driving tests with psychophysiological measures to assist in characterizing personalized cognitive evaluation in the behavioral evaluation process.

Assessing Fitness-To-Drive among Older Drivers: A Comparative Analysis of Potential Alternatives to on-Road Driving Test

To enable older drivers to maintain mobility without endangering public safety, it is necessary to develop more effective means of assessing their fitness-to-drive as alternatives to an on-road driving test. In this study, a functional ability test, simulated driving test, and on-road driving test were carried out for 136 older drivers. Influencing factors related to fitness-to-drive were selected based on the correlation between the outcome measure of each test and the pass/fail outcome of the on-road driving test. Four potential alternatives combining different tests were considered and three modeling techniques were compared when constructing the fitness-to-drive assessment model for the elderly. As a result, 92 participants completed all of the tests, of which 61 passed the on-road driving test and the remaining 31 failed. A total of seven influencing factors from all types of tests were selected. The best model was trained by the technique of gradient boosted machine using all of the seven factors, generating the highest accuracy of 92.8%, with sensitivity of 0.94 and specificity of 0.90. The proposed fitness-to-drive assessment method is considered an effective alternative to the on-road driving test, and the results offer a valuable reference for those unfit-to-drive older drivers to either adjust their driving behavior or cease driving.

Maze test score time adjustments when using nondominant hand in fitness-to-drive assessments

Drivers with medical conditions may need to demonstrate their fitness by participating in clinical and on-road assessments. Scores from the clinic-based occupational therapy-drive home maze test (OT-DHMT) can contribute to fitness-to-drive recommendations. The OT-DHMT is a short, timed test that has previously been shown to be valid and reliable, and norms are available for completion with a driver's dominant hand. Following stroke or trauma, many drivers need to complete assessments and resume driving using their nondominant hand. The validity of a person's OT-DHMT score when completed with a nondominant hand is unknown. This study investigated if a person's OT-DHMT score time requires adjustment when completed with a nondominant hand. The OT-DHMT was administered with a convenience sample of 148 community-dwelling participants, aged 21-81 years (M = 48.6, SD = 19.38) using both their dominant and nondominant hands, in a random order. OT-DHMT score times were significantly faster when using dominant (M = 15.73) compared with nondominant (M = 17.64) hand, d = 1.91 [confidence interval (CI) 1.13, 2.69], t = 4.84, P < 0.01. Employing a generalized weighted least squares regression model indicated that multiplying a driver's nondominant hand time by 0.833 s for drivers aged ≤60, and by 0.929 s for drivers aged 61+ can approximate dominant hand completion times. The OT-DHMT has been validated for use with people using their nondominant hand. Time adjustments are required for people using their nondominant hand when completing the OT-DHMT, and a larger adjustment is required for people aged ≤60 reinforcing previous findings that younger people have faster OT-DHMT completion times.

Development and Evaluation of Maze-Like Puzzle Games to Assess Cognitive and Motor Function in Aging and Neurodegenerative Diseases

There is currently a need for engaging, user-friendly, and repeatable tasks for assessment of cognitive and motor function in aging and neurodegenerative diseases. This study evaluated the feasibility of a maze-like Numberlink puzzle game in assessing differences in game-based measures of cognition and motor function due to age and neurodegenerative diseases. Fifty-five participants, including young (18-31 years, n = 18), older (64-79 years, n = 14), and oldest adults (86-98 years, n = 14), and patients with Parkinson's (59-76 years, n = 4) and Huntington's disease (HD; 35-66 years, n = 5) played different difficulty levels of the Numberlink puzzle game and completed usability questionnaires and tests for psychomotor, attentional, visuospatial, and constructional and executive function. Analyses of Numberlink game-based cognitive (solving time and errors) and motor [mean velocity and movement direction changes (MDC)] performance metrics revealed statistically significant differences between age groups and between patients with HD and older adults. However, patients with Parkinson's disease (PD) did not differ from older adults. Correlational analyses showed significant associations between game-based performance and movement metrics and performance on neuropsychological tests for psychomotor, attentional, visuospatial, and constructional and executive function. Furthermore, varying characteristics of the Numberlink puzzle game succeeded in creating graded difficulty levels. Findings from this study support recent suggestions that data from a maze-like puzzle game provide potential "digital biomarkers" to assess changes in psychomotor, visuoconstructional, and executive function related to aging and neurodegeneration. In particular, game-based movement measures from the maze-like puzzle Numberlink games are promising as a tool to monitor the progression of motor impairment in neurodegenerative diseases. Further studies are needed to more comprehensively establish the cognitive validity and test-retest reliability of using Numberlink puzzles as a valid cognitive assessment tool.

Alzheimer Disease Biomarkers and Driving in Clinically Normal Older Adults: Role of Spatial Navigation Abilities

PURPOSE

Older adults experience impaired driving performance, and modify their driving habits, including limiting amount and spatial extent of travel. Alzheimer disease (AD)-related pathology, as well as spatial navigation difficulties, may influence driving performance and driving behaviors in clinically normal older adults. We examined whether AD biomarkers [cerebrospinal fluid (CSF) concentrations of Aβ42, tau, and ptau181] were associated with lower self-reported spatial navigation abilities, and whether navigation abilities mediated the relationship of AD biomarkers with driving performance and extent.

METHODS

Clinically normal older adults (n=112; aged 65+) completed an on-road driving test, the Santa Barbara Sense of Direction scale (self-report measure of spatial navigation ability), and the Driving Habits Questionnaire for an estimate of driving extent (composite of driving exposure and driving space). All participants had a lumbar puncture to obtain CSF.

RESULTS

CSF Aβ42, but not tau or ptau181, was associated with self-reported navigation ability. Lower self-reported navigation was associated with reduced driving extent, but not driving errors. Self-reported navigation mediated the relationship between CSF Aβ42 and driving extent.

CONCLUSIONS

Findings suggest that cerebral amyloid deposition is associated with lower perceived ability to navigate the environment, which may lead older adults with AD pathology to limit their driving extent.

Investigating Simulated Driving Errors in Amnestic Single- and Multiple-Domain Mild Cognitive Impairment

The areas of driving impairment characteristic of mild cognitive impairment (MCI) remain unclear. This study compared the simulated driving performance of 24 individuals with MCI, including amnestic single-domain (sd-MCI, n = 11) and amnestic multiple-domain MCI (md-MCI, n = 13), and 20 age-matched controls. Individuals with MCI committed over twice as many driving errors (20.0 versus 9.9), demonstrated difficulty with lane maintenance, and committed more errors during left turns with traffic compared to healthy controls. Specifically, individuals with md-MCI demonstrated greater driving difficulty compared to healthy controls, relative to those with sd-MCI. Differentiating between different subtypes of MCI may be important when evaluating driving safety.

A Systematic Review and Meta-Analysis of On-Road Simulator and Cognitive Driving Assessment in Alzheimer's Disease and Mild Cognitive Impairment

BACKGROUND

Many individuals with Alzheimer's disease (AD) and mild cognitive impairment (MCI) are at an increased risk of driving impairment. There is a need for tools with sufficient validity to help clinicians assess driving ability.

OBJECTIVE

Provide a systematic review and meta-analysis of the primary driving assessment methods (on-road, cognitive, driving simulation assessments) in patients with MCI and AD.

METHODS

We investigated (1) the predictive utility of cognitive tests and domains, and (2) the areas and degree of driving impairment in patients with MCI and AD. Effect sizes were derived and analyzed in a random effects model.

RESULTS

Thirty-two articles (including 1,293 AD patients, 92 MCI patients, 2,040 healthy older controls) met inclusion criteria. Driving outcomes included: On-road test scores, pass/fail classifications, errors; caregiver reports; real world crash involvement; and driving simulator collisions/risky behavior. Executive function (ES [95% CI]; 0.61 [0.41, 0.81]), attention (0.55 [0.33, 0.77]), visuospatial function (0.50 [0.34, 0.65]), and global cognition (0.61 [0.39, 0.83]) emerged as significant predictors of driving performance. Trail Making Test Part B (TMT-B, 0.61 [0.28, 0.94]), TMT-A (0.65 [0.08, 1.21]), and Maze test (0.88 [0.60, 1.15]) emerged as the best single predictors of driving performance. Patients with very mild AD (CDR = 0.5) mild AD (CDR = 1) were more likely to fail an on-road test than healthy control drivers (CDR = 0), with failure rates of 13.6%, 33.3% and 1.6%, respectively.

CONCLUSION

The driving ability of patients with MCI and AD appears to be related to degree of cognitive impairment. Across studies, there are inconsistent cognitive predictors and reported driving outcomes in MCI and AD patients. Future large-scale studies should investigate the driving performance and associated neural networks of subgroups of AD (very mild, mild, moderate) and MCI (amnestic, non-amnestic, single-domain, multiple-domain).

The Key of the Maze: The role of mental imagery and cognitive flexibility in navigational planning

Spatial navigation planning ability relies on both mental imagery and cognitive flexibility. Considering the importance of planning ability in everyday life, several neuropsychological tests are used in clinical practice for its assessment, although some of these are not aimed at assessing the strategies of navigational planning. The Porteus Maze Test (PMT) and the Key Search Task (KST) require to plan a strategy in a maze and in an imagined space, respectively. To the best of our knowledge, although these two tests share some features, the relationship between them has never been explored. The purpose of the present study was to investigate, for the first time, the relationship between the PMT and the KST performances in 38 healthy subjects in order to understand the implications of this association for the assessment of spatial navigation ability. Subjects were subdivided in bad or good navigation planners on the basis of the their KST score. The results of the study have revealed a significant difference (t=2.35; p=0.03) in the number of errors made at the PMT by bad navigational planners (0.78±0.28) and good navigational planners (0.10±0.06). The first group (bad navigational planners) made more errors at the PMT than the good navigational planners (who made less errors at the PMT). This provides evidence of the possibility to use the KST and the PMT in a combined way as a new tool for the assessment of spatial navigational planning ability. Furthermore, this finding highlights the importance of mental imagery and cognitive flexibility in spatial navigation, suggesting that these functions could be the link between a good planning ability and a successful spatial navigation. In conclusion, this study suggests that an efficient navigation would not be possible without a good navigational planning ability.

Hierarchical Mazes in Psychological Research

Hierarchical mazes have been used in psychology for more than 100 years. During this time many different maze tasks have been created and used to test.cognitive processes and distinguish personality traits. Some of these mazes seem better than others to test different abilities. This article describes the most important mazes used in psychological research and the most important procedures used with these mazes. More than 20 different hierarchical mazes (including maze sets with more than 1 maze, e.g., those of Porteus and Elithorn) were analyzed and classified to different categories.

Preliminary Investigation on the Association between Depressive Symptoms and Driving Performance in Heart Failure

Heart failure (HF) patients commit many errors on driving simulation tasks and cognitive dysfunction appears to be one important contributor to impaired driving in HF. Clinical modifiers of cognition may also play a key role. In particular, depression is common in HF patients, linked with cognitive dysfunction, and contributes to reduced driving fitness in non-HF samples. However, the associations among depressive symptoms, cognition, and driving in HF are unclear. Eighteen HF patients completed a validated simulated driving scenario, the Beck Depression Inventory-II (BDI-II), and a cognitive test battery. Partial correlations controlling for demographic and medical confounds showed higher BDI-II score correlated with greater number of collisions, centerline crossings, and % time out of lane. Increased depressive symptoms correlated with lower attention/executive function, and reduced performance in this domain was associated with a greater number of collisions, centerline crossing, and % time out of lane. Depressive symptoms may be related to poorer driving performance in HF, perhaps through association with cognitive dysfunction. However, larger studies with on-road testing are needed to replicate our preliminary findings before recommendations for clinical practice can be made.

Screening and assessment tools for determining fitness to drive: a review of the literature for the pathways project

With a brief introduction, 10 tables summarize the findings from the literature describing screening and assessment tools used with older adults to identify risk or determine fitness to drive. With a focus on occupational therapy's duty to address driving as a valued activity, this paper offers information about tools used by occupational therapy practitioners across practice settings and specialists in driver rehabilitation. The tables are organized into groups of key research studies of assessment tools, screening batteries, tools used in combination (i.e., as a battery), driving simulation as an assessment tool, and screening/assessment for individuals with stroke, vision impairment, Parkinson's disease, dementia, and aging. Each table has a summary of important concepts to consider as occupational therapists choose the methods and tools to evaluate fitness to drive.

Driving and dementia: a clinical decision pathway

OBJECTIVE

This study aimed to develop a pathway to bring together current UK legislation, good clinical practice and appropriate management strategies that could be applied across a range of healthcare settings.

METHODS

The pathway was constructed by a multidisciplinary clinical team based in a busy Memory Assessment Service. A process of successive iteration was used to develop the pathway, with input and refinement provided via survey and small group meetings with individuals from a wide range of regional clinical networks and diverse clinical backgrounds as well as discussion with mobility centres and Forum of Mobility Centres, UK.

RESULTS

We present a succinct clinical pathway for patients with dementia, which provides a decision-making framework for how health professionals across a range of disciplines deal with patients with dementia who drive.

CONCLUSIONS

By integrating the latest guidance from diverse roles within older people's health services and key experts in the field, the resulting pathway reflects up-to-date policy and encompasses differing perspectives and good practice. It is potentially a generalisable pathway that can be easily adaptable for use internationally, by replacing UK legislation for local regulations. A limitation of this pathway is that it does not address the concern of mild cognitive impairment and how this condition relates to driving safety.

Cognitive and visual predictors of UFOV performance in older adults

Eighty two community dwelling older adults (52 females) aged 62-92 years (mean=75) completed a battery of cognitive and visual tests selected to assess functions relevant to driving performance. These were visual acuity, contrast sensitivity, general mental competence (Mini Mental State Examination, MMSE), processing speed (Inspection Time, IT), crowding across the visual field (Proficiency of Peripheral Vision Processing, ProPerVis) and change detection (DriverScan). These six tasks provided predictor variables for performance on the Useful Field of View test (UFOV), a well validated test of fitness to drive that includes subtests for (i) processing speed; (ii) divided attention; and (iii) selective attention. Relative importance regression analyses confirmed that UFOV is sensitive to attentional and speed processes but suggested that subtest (i) primarily reflects visual acuity and contrast sensitivity; subtest (ii) is better explained by change detection and processing speed; and subtest (iii) predominantly reflects crowding and contrast sensitivity. Unexpectedly, given no evidence of substantial cognitive decline, MMSE contributed significantly to performance on the more complex subtests (ii) and (iii).

Systematic review of appropriate cognitive assessment instruments used in clinical trials of schizophrenia, major depressive disorder and bipolar disorder

Cognitive dysfunction is increasingly recognized as a symptom in mental conditions including schizophrenia, major depressive disorder (MDD), and bipolar disorder (BPD). Despite the many available cognitive assessment instruments, consensus is lacking on their appropriate use in clinical trials. We conducted a systematic literature review in Embase, PubMed/Medline and PsychINFO to identify appropriate cognitive function instruments for use in clinical trials of schizophrenia, MDD, and BPD. Instruments were identified from the articles. Instruments and articles were excluded if they did not address schizophrenia, MDD, or BPD. Instrument appropriateness was further assessed by the criteria of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative: test-retest reliability, utility, relationship to functional status, potential changeability to pharmacological agents, and tolerability and practicality for clinical trials. The database search yielded 173 articles describing 150 instruments used to assess cognitive function. Seventeen additional instruments were identified through Google and clinicaltrials.gov. Among all these, only 30 (18%) were deemed appropriate for use in the diseases of interest. Of these, 27 were studied in schizophrenia, one in MDD and two in BPD. These findings suggest the need for careful selection of appropriate cognitive assessment instruments, as not all may be valid in these disorders.

Mild cognitive impairment: safe to drive?

Driving is an important aspect of daily living and for many older people provides autonomy and psycho-social benefits. Cognitive impairment has been found to impact driving skills at the level of dementia, however, uncertainty remains around the impact of a diagnosis of the pre-dementia condition mild cognitive impairment. Current official guidelines are unclear, and assessment of fitness to drive can be problematical. This editorial examines current official guidance available to the clinician and problems with existing assessment as well as the current position of research specifically into MCI and driving, and considers future direction for research in this field.

Medications and impaired driving

OBJECTIVE

To describe the association of specific medication classes with driving outcomes and provide clinical recommendations.

DATA SOURCES

The MEDLINE and EMBASE databases were searched for articles published from January 1973 to June 2013 on classes of medications associated with driving impairment. The search included outcome terms such as automobile driving, motor vehicle crash, driving simulator, and road tests.

STUDY SELECTION AND DATA EXTRACTION

Only English-language articles that contained findings from observational or interventional designs with ≥ 10 participants were included in this review. Cross-sectional studies, case series, and case reports were excluded.

DATA SYNTHESIS

Driving is an important task and activity for the majority of adults. Some commonly prescribed medications have been associated with driving impairment measured by road performance, driving simulation, and/or motor vehicle crashes. This review of 30 studies identified findings with barbiturates, benzodiazepines, hypnotics, antidepressants, opioid and nonsteroidal analgesics, anticonvulsants, antipsychotics, antiparkinsonian agents, skeletal muscle relaxants, antihistamines, anticholinergic medications, and hypoglycemic agents. Additional studies of medication impact on sedation, sleep latency, and psychomotor function, as well as the role of alcohol, are also discussed.

CONCLUSIONS

Psychotropic agents and those with central nervous system side effects were associated with measures of impaired driving performance. It is difficult to determine if such associations are actually a result of medication use or the medical diagnosis itself. Regardless, clinicians should be aware of the increased risk of impaired driving with specific classes of medications, educate their patients, and/or consider safer alternatives.

Systematic review of the evidence for Trails B cut-off scores in assessing fitness-to-drive

Background

Fitness-to-drive guidelines recommend employing the Trail Making B Test (a.k.a. Trails B), but do not provide guidance regarding cut-off scores. There is ongoing debate regarding the optimal cut-off score on the Trails B test.

The objective of this study was to address this controversy by systematically reviewing the evidence for specific Trails B cut-off scores (e.g., cut-offs in both time to completion and number of errors) with respect to fitness-to-drive.

Methods

Systematic review of all prospective cohort, retrospective cohort, case-control, correlation, and cross-sectional studies reporting the ability of the Trails B to predict driving safety that were published in English-language, peer-reviewed journals.

Results

Forty-seven articles were reviewed. None of the articles justified sample sizes via formal calculations. Cut-off scores reported based on research include: 90 seconds, 133 seconds, 147 seconds, 180 seconds, and < 3 errors.

Conclusions

There is support for the previously published Trails B cut-offs of 3 minutes or 3 errors (the ‘3 or 3 rule’). Major methodological limitations of this body of research were uncovered including (1) lack of justification of sample size leaving studies open to Type II error (i.e., false negative findings), and (2) excessive focus on associations rather than clinically useful cut-off scores.

Assessment of driving-related skills prediction of unsafe driving in older adults in the office setting

OBJECTIVES

To examine the sensitivity and specificity of the Assessment of Driving-Related Skills (ADReS), a clinical tool recommended by the American Medical Association for identifying potentially unsafe older drivers that includes tests of vision, motor function, and cognition.

DESIGN

Cross-sectional observation study.

SETTING

Memory assessment outpatient clinic of a university hospital.

PARTICIPANTS

Drivers with normal cognition (n = 47) and cognitive impairment (n = 75).

MEASUREMENTS

A neurologist completed the ADReS during an office visit. Additional cognitive tests of executive, visuospatial, and visuomotor function were also performed. On a separate day, participants completed a standardized on-road test, assessed by a professional driving instructor using a global safety rating and a quantitative driving score.

RESULTS

In this sample of currently active older drivers with and without cognitive impairment, measures of cognition-particularly the Trail-Making Test Part B-were more highly correlated with driving scores than other measures of function. Using recommended scoring procedures, the ADReS had a sensitivity of 0.81 for detecting impaired driving on the road test, with a specificity of 0.32 and an area under the receiver operating characteristic curve (AUC) of 0.57. A logistic regression model that incorporated computerized maze task and Mini-Mental State Examination scores improved overall classification accuracy, yielding a sensitivity of 0.61, a specificity of 0.84, and an AUC of 0.80.

CONCLUSION

In its present form, the ADReS has limited utility as an office screen for individuals who should undergo formal driving assessment. Improved scoring methods and screening tests with greater diagnostic accuracy than the ADReS are needed for general office practice.

The Maze Test: A significant predictor of older driver crash risk

A study sponsored by the National Highway Traffic Safety Administration performed functional assessments on approximately 700 drivers age 70 and older who presented for license renewal in urban, suburban, and rural offices of the Maryland Motor Vehicle Administration. This volunteer sample received a small compensation for study participation, with an assurance that their license status would not be affected by the results. A comparison with all older drivers who visited the same sites on the same days indicated that the study sample was representative of Maryland older drivers with respect to age and prior driving safety indices. Relationships between drivers' scores on a computer touchscreen version of the Maze Test and prospective crash and serious moving violation experience were analyzed. Results identified specific mazes as highly significant predictors of future safety risk for older drivers, with a particular focus on non-intersection crashes. Study findings indicate that performance on Maze Tests was predictive of prospective crashes and may be useful, as a complement to other, established cognitive screening tools, in identifying at-risk older drivers.

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.

Validity of the Occupational Therapy-Drive Home Maze Test for right and left handed test takers

The Occupational Therapy-Drive Home Maze Test (OT-DHMT) is part of the OT-DORA Battery used in licensing recommendations for older and/or functionally impaired drivers. Previously published research has been conducted to investigate the predictive validity, inter-rater reliability and establish norms for this timed test with normal and cognitively impaired drivers. Anecdotal evidence from this research indicated there could be a bias against right-handers (dextrals) who may need to lift their hand to view the maze, thus increasing the time taken. Therefore this study investigated the validity of the OT-DHMT when administered to left and right handed individuals. The OT-DHMT was individually administered to a new sample of 144 healthy drivers aged 18-69 years. From this, 34 participant pairs were matched for age and gender, according to their dexterity. The results show that there were no significant differences in time taken when completing the maze test, for participants who complete the test with either writing hand t(33)=1.59, p=0.12 (95%CI: -0.63 to 5.08). While further testing is required with samples from different cultures and with more participants aged 30-69 and 70 years and over to extend generalizability of these findings, the results suggest the OT-DHMT is suitable to be administered and scored using the methods published as part of the OT-DORA Battery.

Road test and naturalistic driving performance in healthy and cognitively impaired older adults: does environment matter?

OBJECTIVES

To relate the standardized road test to video recordings of naturalistic driving in older adults with a range of cognitive impairment.

DESIGN

Cross-sectional observational study.

SETTING

Academic medical center memory disorders clinic.

PARTICIPANTS

One hundred three older drivers (44 healthy, 59 with cognitive impairment) who passed a road test.

MEASUREMENTS

Error rate and global ratings of safety (pass with and without recommendations, marginal with restrictions or training, or fail) made by a professional driving instructor.

RESULTS

There was fair agreement between global ratings on the road test and naturalistic driving. More errors were detected in the naturalistic environment, but this did not affect global ratings. Error scores between settings were significantly correlated, and the types of errors made were similar. History of crashes corrected for miles driven per week was related to road test error scores but not naturalistic driving error scores. Global cognition (Mini-Mental State Examination) was correlated with road test and naturalistic driving errors. In healthy older adults, younger age was correlated with fewer errors on the road test and more errors in naturalistic driving.

CONCLUSION

Road test performance is a reasonable proxy for estimating fitness to drive in older individuals' typical driving environments, but differences between performance assessed using these two methods remain poorly understood and deserve further study.

Development of a standardised Occupational Therapy--Driver Off-Road Assessment Battery to assess older and/or functionally impaired drivers

INTRODUCTION

Research has been conducted over several years to develop a new off-road assessment battery referred to as the Occupational Therapy - Driver Off-Road Assessment Battery. This article documents the development of the Battery, and provides preliminary research evidence to support its content and predictive validity.

METHODS

Literature reviews and a focus group with nine driver assessor occupational therapists were undertaken, as well as data collection using the Occupational Therapy - Driver Off-Road Assessment Battery with 246 clients. A Classification and Regression Tree model was constructed to ascertain the predictive validity of the Battery, with fitness-to-drive as the outcome.

RESULTS

Twenty-one physical, 13 sensory and seven assessments of cognition/perception were identified as being reflective of the skills required for driving. Following rating of their psychometric properties, the best assessments were presented to focus group members. The driver assessors supported the inclusion of several assessments and encouraged the development of new assessments. A draft version of the Occupational Therapy - Driver Off-Road Assessment Battery was tested and found to have excellent predictive validity for client on-road performance of 82.6%. The Classification and Regression Tree model showed that client performance on tests included in the Battery should be used together, rather than in isolation, to support fitness-to-drive recommendations.

CONCLUSION

This research identified the most suitable physical, sensory and cognitive assessments to include in the Occupational Therapy - Driver Off-Road Assessment Battery, and provided support for its validity. The development of this standardised battery assists driver assessors to accurately and consistently assess and report the off-road driving capacity of clients.

Assessing executive function in relation to fitness to drive: a review of tools and their ability to predict safe driving

BACKGROUND/AIM

The assessment of executive functions is an integral component in determining fitness to drive. A structured review was conducted to identify assessment tools used to measure executive function in relation to driving and to describe these tools according to: (i) specific executive function components assessed; (ii) the tool's validity in predicting safe driving; and (iii) clinical utility.

METHODS

Sixty-nine articles were reviewed, identifying 53 executive function tools/assessments used in driving research. Each tool was critically appraised and the findings were compiled in a Driving Executive Function Tool Guide.

RESULTS

Among the 53 tools, there were 27 general assessments of cognition, 19 driving-specific and seven activities of daily living/instrumental activities of daily living assessments. No single tool measured all executive function components: working memory was the most common (n = 20/53). Several tools demonstrated strong predictive validity and clinical utility. For example, tools, such as the Trail Making Test and the Maze Task, have the shortest administration time (i.e. often less than 10 minutes) and the most easily accessible method of administration (i.e. pen and paper or verbal). Driving-specific tools range from short questionnaires, such as the 10-minute Manchester Driving Behaviour Questionnaire, to more complex tools requiring about 45 minutes to administer. CONCLUSIONS AND SIGNIFICANCE OF THE STUDY: The appropriateness of a tool depends on the individual being assessed and on practical constraints of the clinical context. The Driving Executive Function Tool Guide provides useful information that should facilitate decision-making and selection of appropriate executive function tools in relation to driving.

Predicting road test performance in drivers with dementia

OBJECTIVES

To develop a cognitive and functional screening battery for the on-road performance of older drivers with dementia.

DESIGN

Prospective observational study.

SETTING

On-road driving evaluation clinic at an academic rehabilitation center.

PARTICIPANTS

Ninety-nine older people with dementia (63% male, mean age 74.2 ± 9), referred by community physicians to an occupational therapy driving clinic.

MEASUREMENTS

The outcome variable was pass or fail on the modified Washington University Road Test. Predictor measures were tests of visual, motor, and cognitive functioning, selected for their empirical or conceptual relationship to the complex task of driving safely.

RESULTS

Sixty-five (65%) participants failed the on-road driving test. The best predictive model, with an overall accuracy of up to 85% when participants were blinded, included the Eight-item Informant Interview to Differentiate Aging and Dementia, Clock Drawing Test score, and time to complete the Snellgrove Maze Test or Trail Making Test Part A. Visual and motor functioning were not associated with road test failure.

CONCLUSION

A screening battery that could be performed in less than 10 minutes predicted with good accuracy failure rate for the on-road driving test in this sample of older drivers with dementia. A probability of failure calculator is provided from a logistic regression model that may be useful for clinicians in their decision to refer impaired older adults for further testing. More studies are needed in larger community-based samples, along with discussions with patients, families, and clinicians, with regard to acceptable levels of test uncertainty.

Normative data, preliminary inter-rater reliability and predictive validity of the Drive Home Maze Test

OBJECTIVE

The Drive Home Maze Test has been developed as part of a clinic-based driver assessment battery. This article reports normative data and preliminary inter-rater reliability for this test together with predictive validity for a clinical sample.

SUBJECTS AND SETTING

223 individuals contributed to the normative data. Of these, data from 42 clients undergoing driver assessment as part of their rehabilitation or health care plan were used to ascertain the predictive validity of the Drive Home Maze Test for on-road driving performance (Pass/ Fail).

MAIN MEASURE

The Drive Home Maze Test was developed for occupational therapy driver assessors to use with all older and/ or functionally impaired drivers prior to on-road testing. The test assesses a person s executive function, attention and visuoconstructive skills.

RESULTS

The normative data indicated that time taken and number of errors on the maze increases with age. Performance on this test was strongly indicative of driver assessment outcome using the regression model: ln(Odds of failing on road) = 5.9451 + 2.7047 (log10 time taken to complete the maze). Excellent preliminary inter-rater reliability was also found using Ordinary Least Products linear regression analysis to test for bias between two raters for time taken and number of errors on the maze, with values ranging from r = 0.858 to 0.999.

CONCLUSIONS

The Drive Home Maze Test provides useful information concerning a person's cognitive skills prior to undertaking an on-road assessment. Time taken to complete this test is indicative of the outcome of an on-road driver assessment.

Effects of cholinesterase inhibitors on visual attention in drivers with Alzheimer disease

OBJECTIVE

We conducted a combined observational cohort and case-control study in patients with Alzheimer disease (AD) to assess the effects of acetylcholinesterase inhibitor (ChEI) treatment on cognitive functions important for driving.

METHODS

Performance of 24 outpatients with newly diagnosed (untreated) early-stage AD was compared before beginning ChEI (pre-ChEI) and after 3 months of therapy (post-ChEI) on a set of computerized tests of visual attention and executive function administered under both single-task and dual-task conditions. To address the limitation of a lack of an untreated control group in this observational cohort study, performance of 35 outpatients with newly diagnosed (untreated) early-stage AD (ChEI nonusers) were also compared with a demographically matched group of AD patients treated with stable doses of a ChEI (ChEI users) on these tasks.

RESULTS

Performance was consistently worse under dual-task than single-task conditions regardless of ChEI treatment status. However, ChEI treatment consistently affected specific components of attention within each test across both sets of comparisons: ChEI treatment enhanced simulated driving accuracy and was associated with significantly better visual search target detection accuracy and response time in both pre-ChEI-post-ChEI and users-nonusers treatment comparisons. Cholinesterase inhibitor treatment also improved overall time to complete a set of mazes while not affecting accuracy of completion.

CONCLUSIONS

Cholinesterase inhibitor treatment was associated with improvements in tests of executive function and visual attention. These findings could have important implications for patients who continue to drive in the early stages of AD.

Test Acceptability and Confidence Levels in Older Adults Referred for Fitness-to-Drive Evaluations

In this study, we examined confidence and face validity or client acceptability of tests used in a Veterans Affairs Medical Center driving clinic. The clinic used evidence-based off-road tests and adopted the Washington University Road Test (WURT) as a performance-based on-road examination. Forty-three clients consented to participate in the study; most were male with an average age of 78.2 years (standard deviation = 12.6). In general, a trend existed toward higher client acceptability of tests adopted from the Neuropsychological Assessment Battery (Stern & White, 2003) and the WURT than of other off-road measures. Confidence decreased after administration of the psychometric test battery, yet it increased after the on-road evaluations despite a 47% failure rate in the sample. Additional study is needed on test acceptability because it may have the potential to increase understanding, compliance, or both with driving recommendations. Additional research is also needed to examine client confidence levels and their potential impact on performance during the driving evaluation process.

How does dementia affect driving in older patients?

Driving is a complex activity that always becomes impaired at some point in older adults with degenerative dementia. Over time, disruption of the visual processing circuits of the brain that link the occipital and prefrontal regions, particularly in the right hemisphere, leads to increasing degrees of driving impairment that ultimately preclude safe driving. Neuropsychological tests of visuospatial ability, executive function and attention that tap into the integrity of these brain regions provide the clinician with important information regarding the need for a formal determination of driving competence. Enhancement of cognitive function in these domains through anti-dementia therapy and exercise may partially mitigate risk; however, all drivers with dementia must ultimately retire from driving when dementia becomes moderately severe, and often in earlier stages of the illness. Future efforts to improve screening tests for hazardous driving and to develop interventions to help prolong the time that drivers with mild dementia can continue to drive safely are needed for our increasingly aged and mobile population.

Egocentric and exocentric navigation skills in older adults

BACKGROUND

Human spatial navigation can be conceptualized as egocentric or exocentric, depending on the navigator's perspective. Navigational impairment is known to occur in individuals with cognitive impairment, but less is known about navigational abilities in nondemented older adults. Our objective was to develop tests of navigation and study their cognitive correlates in nondemented older adults.

METHODS

We developed a Local Route Recall Test (LRRT) to examine egocentric navigation and a Floor Maze Test (FMT) to assess exocentric navigation in 127 older adults without dementia or amnestic Mild Cognitive Impairment (MCI). Factor analysis was used to reduce neuropsychological test scores to three cognitive factors representing Executive Function/Attention, Verbal Ability, and Memory. We examined relationships between navigational tests and cognitive function (using both cognitive factors and the highest loading individual test on each factor) in a series of regression analyses adjusted for demographic variables (age, sex, and education), medical illnesses, and gait velocity.

RESULTS

The tests were well tolerated, easy to administer, and reliable in this nondemented and non-MCI sample. Egocentric skills on the LRRT were associated with Executive Function/Attention (B = -0.650; 95% confidence interval [CI], -0.535 to -0.139) and Memory (B = -0.518; 95% CI, -4.893 to -0.063) factors. Exocentric navigation on the FMT was related to Executive Function/Attention (B = -8.542; 95% CI, -13.357 to -3.727).

CONCLUSIONS

Our tests appear to assess egocentric and exocentric navigation skills in cognitively normal older adults, and these skills are associated with specific cognitive processes such as executive function and memory.

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.

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.

Clinician assessment of the driving competence of patients with dementia

OBJECTIVES

To determine the validity and reliability of clinician ratings of the driving competence of patients with mild dementia.

DESIGN

Observational study of a cross-section of drivers with mild dementia based on chart review by clinicians with varying types of expertise and experience.

SETTING

Outpatient dementia clinic.

PARTICIPANTS

Fifty dementia subjects from a longitudinal study of driving and dementia.

MEASUREMENTS

Each clinician reviewed information from the clinic charts and the first study visit. The clinician then rated the drivers as safe, marginal, or unsafe. A professional driving instructor compared these ratings with total driving scores on a standardized road test and categorical ratings of driving competence. Clinicians also completed a visual analog scale assessment of variables that led to their determinations of driving competence.

RESULTS

Accuracy of clinician ratings ranged from 62% to 78% for the instructor's global rating of safe versus marginal or unsafe. In general, there was moderate accuracy and interrater reliability. Accuracy could have been improved in the least-accurate raters by greater attention to dementia duration and severity ratings, as well as less reliance on the history and physical examination. The most accurate predictors were clinicians specially trained in dementia assessment, who were not necessarily the most experienced in their years of clinical experience.

CONCLUSION

Although a clinician may be able to identify many potentially hazardous drivers, accuracy is insufficient to suggest that a clinician's assessment alone is adequate to determine driving competence in those with mild dementia.

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.

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.