Predicting driving performance in older adults: we are not there yet!

Serial Trichotomization to Determine Fitness to Drive: Results From a Cohort of Clients Referred to a Neurology Program

IMPORTANCE

Determining cognitive fitness to drive is challenging. A previous study used serial trichotomization with five cognitive tests to determine whether drivers should continue driving, undergo further evaluation, or stop driving.

OBJECTIVE

To examine agreement between serial trichotomization and fitness-to-drive determinations made by occupational therapists.

DESIGN

Drivers referred for cognitive screens completed all tests used in the previous study. Occupational therapists provided fitness-to-drive recommendations (safe, indeterminate, or unsafe) using all clinical information available. We examined the agreement between the tests' results (using cut points from the previous study) and occupational therapists' recommendations.

SETTING

Outpatient neurology program at a chronic care and rehabilitation hospital.

PARTICIPANTS

279 clients (M age  = 66.35 yr; SD = 13.25).

OUTCOMES AND MEASURES

Tests included the Trail Making Tests A and B, the Clock Drawing Test (CDT), the Montreal Cognitive Assessment, and the Motor-Free Visual Perception Test, using a road test as the gold standard. The previous study used dual cut points with 100% sensitivity and specificity to reduce false positives and false negatives.

RESULTS

Weighted κs ranged from .03 (95% confidence interval [CI] [-.01, .08]) for the CDT to .54 (95% CI [.46, .62]) for the Trail Making Test, Part B. Although the agreement between serial trichotomization and the final recommendations was moderate (κ = .59; 95% CI [.50, .67]), serial trichotomization appeared useful for identifying unsafe drivers.

CONCLUSIONS AND RELEVANCE

These results remind us of the variability inherent in stand-alone cognitive tests, even within a serial trichotomization framework, and the importance of clinical judgement and road tests in decision making about driving. Plain-Language Summary: It can be challenging for occupational therapists to accurately determine a client's cognitive fitness to drive. Many occupational therapists lack the time, have limited training, or do not have access to comprehensive driving evaluation tools. A serial testing approach can support occupational therapists in assessing a client's cognitive fitness to drive. This study used an approach based on a series of five cognitive tests to determine whether a client should continue driving, undergo further evaluation, or stop driving. The series of tests were used to classify drivers as safe, indeterminate, or unsafe. In principle, a driver would take the second test only if the driver was classified as indeterminate on the basis of first test, and so on. By applying the tests in sequence, few drivers should remain classified as indeterminate at the end of the series of tests. This serial approach has the potential to streamline the decision-making process for occupational therapists by classifying the more extreme unsafe cases while still providing an accurate assessment of cognitive fitness to drive.

Older adult driving performance assessed under simulated and on-road conditions

Simulated driving offers a convenient test of driving ability for older drivers, although the viability of using simulated driving with this population is mixed. The relative weighting of the relevant perceptual, cognitive, and physical factors may vary between simulated and on-road driving. The current study was designed to assess this possibility. We conducted simulated and on-road driving tests of 61 older adults aged 66-92 years. To ensure that the driving performance was measured similarly between the two driving modalities, we employed the Record of Driving Errors (RODE) driving assessment system during both driving tests. Correlation and random weights analysis (RWA) results indicated only modest evidence of correspondence between the simulated and on-road driving performances. The primary factors operative in both simulated and on-road driving was Useful Field of View and a measure of basic cognition. Unique factors for simulated driving included a measure of physical mobility (Time-Up-and-Go) and spatial reasoning (Line), and for on-road driving included chronological age and sensorimotor processing (Trail-Making Task A). Chronological age was correlated primarily the on-road rather than simulated test, was greatly reduced with the inclusion of additional explanatory factors, and likely reflects driving efficiency rather than driving safety. We conclude that simulated driving in healthy older drivers can be beneficial for research purposes to assess cognitive and perceptual factors that underly driving effectiveness, although it cannot serve as a clear proxy for on-road driving.

Driving Errors Predicting Pass/Fail On-Road Assessment Outcomes Among Cognitively Impaired Older Drivers

Older drivers with cognitive impairment (CI)/dementia make significantly more driving errors than healthy controls; however, whether driving errors are predictive of pass/fail outcomes in older drivers with CI/dementia are unclear. This study determined the driving errors that predicted failing an on-road assessment in drivers with CI. We retrospectively collected comprehensive driving evaluation data of 80 participants (76.1 ± 9.3 years) from an Ontario driving assessment center. Adjustment to stimuli (area under the curve [AUC] = 0.88), lane maintenance (AUC = 0.84), and speed regulation errors (AUC = 0.85) strongly predicted pass/fail outcomes. Worse performance on the Trails B (time) and Useful Field of View® (Subtest 2, Subtest 3, and risk index) were significantly correlated with adjustment to stimuli (p < .05), lane maintenance (p < .05), and speed regulation errors (p < .05). Adjustment to stimuli, lane maintenance, and speed regulation errors may be critical indicators of failing an on-road assessment in older drivers with CI. Prioritizing these errors may help identify at-risk drivers.

Predicting Fitness to Drive for Medically At-Risk Drivers Using Touchscreen DriveSafe DriveAware

IMPORTANCE

Occupational therapists require valid cognitive fitness-to-drive tools to advise drivers in this high-stakes area.

OBJECTIVE

To examine the psychometric properties and predictive validity of data gathered with the touchscreen DriveSafe DriveAware (DSDA).

DESIGN

Prospective study that compared a screening tool with a criterion standard.

SETTING

Ten community- and hospital-based driver assessment clinics in Australia and New Zealand.

PARTICIPANTS

Older and cognitively impaired drivers (N = 134) ages 18 to 91 years (Mage= 68) who were referred for an assessment to determine the impact of a medical condition on driving. The inclusion criteria were a valid driver's license, vision within license authority guidelines, completion of at least 1 year of high school, and English as a first language.

OUTCOMES AND MEASURES

The results of the touchscreen DSDA, a standardized assessment of awareness of the driving environment and one's own driving abilities, were compared with those of a standardized occupational therapist-administered on-road assessment.

RESULTS

Rasch analysis provided evidence for the construct validity and internal reliability of data gathered with the touchscreen DSDA. Optimal upper and lower cutoff scores were set to trichotomize drivers into three categories: likely to pass an on-road assessment, likely to fail an on-road assessment, and further testing required. Specificity of the touchscreen DSDA was 86%, and sensitivity was 91%; positive predictive value was 83%, negative predictive value was 92%, and overall accuracy of classification was 88%.

CONCLUSIONS AND RELEVANCE

Evidence supports the utility of the touchscreen DSDA for accurately predicting which participants require on-road assessment. What This Article Adds: The touchscreen DSDA is a promising screen for occupational therapists and other health professionals to use in conjunction with other clinical indicators to determine whether drivers require further assessment.

Modelling the relationship of driver license and offense history with fatal and serious injury (FSI) crash involvement

INTRODUCTION

Previous research has indicated that increases in traffic offenses are linked to increased crash involvement rates, making reductions in offending an appropriate measure for evaluating road safety interventions in the short-term. However, the extent to which traffic offending predicts fatal and serious injury (FSI) crash involvement risk is not well established, prompting this new Victorian (Australia) study.

METHOD

A preliminary cluster analysis was performed to describe the offense data and assess FSI crash involvement risk for each cluster. While controlling demographic and licensing variables, the key traffic offenses that predict future FSI crash involvement were then identified. The large sample size allowed the use of machine learning methods such as random forests, gradient boosting, and Least Absolute Shrinkage and Selection Operator (LASSO) regression. This was done for the 'all driver' sample and five sometimes overlapping groups of drivers; the young, the elderly, and those with a motorcycle license, a heavy vehicle license endorsement and/or a history of license bans.

RESULTS

With the exception of the group of drivers who had a history of bans, offense history significantly improved the accuracy of models predicting future FSI crash involvement using demographic and licensing data, suggesting that traffic offenses may be an important factor to consider when analyzing FSI crash involvement risk and the effects of road safety countermeasures.

CONCLUSIONS

The results are helpful for identifying driver groups to target with further road safety countermeasures, and for showing that machine learning methods have an important role to play in research of this nature. Practical Application: This research indicates with whom road safety interventions should particularly be applied. Changes to driver demerit policies to better target offenses related to FSI crash involvement and repeat traffic offenders, who are at greater risk of FSI crash involvement, are recommended.

The Multiple Object Avoidance (MOA) task measures attention for action: Evidence from driving and sport

Performance in everyday tasks, such as driving and sport, requires allocation of attention to task-relevant information and the ability to inhibit task-irrelevant information. Yet there are individual differences in this attentional function ability. This research investigates a novel task for measuring attention for action, called the Multiple Object Avoidance task (MOA), in its relation to the everyday tasks of driving and sport. The aim in Study 1 was to explore the efficacy of the MOA task to predict simulated driving behaviour and hazard perception. Whilst also investigating its test-retest reliability and how it correlates to self-report driving measures. We found that superior performance in the MOA task predicted simulated driving performance in complex environments and was superior at predicting performance compared to the Useful Field of View task. We found a moderate test-retest reliability and a correlation between the attentional lapses subscale of the Driving Behaviour Questionnaire. Study 2 investigated the discriminative power of the MOA in sport by exploring performance differences in those that do and do not play sports. We also investigated if the MOA shared attentional elements with other measures of visual attention commonly attributed to sporting expertise: Multiple Object Tracking (MOT) and cognitive processing speed. We found that those that played sports exhibited superior MOA performance and found a positive relationship between MOA performance and Multiple Object Tracking performance and cognitive processing speed. Collectively, this research highlights the utility of the MOA when investigating visual attention in everyday contexts.

Protocol for the conceptualization and evaluation of a screening-tool for fitness-to-drive assessment in older people with cognitive impairment

Introduction

Due to aging and health status people may be subjected to a decrease of cognitive ability and subsequently also a decline of driving safety. On the other hand there is a lack of valid and economically applicable instruments to assess driving performance.

Objective

The study is designed to develop a valid screening-tool for fitness-to-drive assessment in older people with cognitive impairment externally validated on the basis of on-road driving performance.

Methods

In a single-centre, non-randomized cross-sectional trial cognitive functioning and on-road-driving-behavior of older drivers will be assessed. Forty participants with cognitive impairment of different etiology and 40 healthy controls will undergo an extensive neuropsychological assessment. Additionally, an on-road driving assessment for external validation of fitness to drive will be carried out. Primary outcome measures will be performance in attention, executive functions and visuospatial tasks that will be validated with respect to performance on the on-road-driving-test. Secondary outcome measures will be sociodemographic, clinical- and driving characteristics to systematically examine their influence on the prediction of driving behavior.

Discussion

In clinical practice counselling patients with respect to driving safety is of great relevance. Thus, having valid, reliable, time economical and easily interpretable screening-tools on hand to counsel patients is of great relevance for practitioners.

Ethics and dissemination

Ethics approval was obtained from the Ethics Committee at the Ludwig-Maximilians-University Munich. The trial results will be disseminated through peer-reviewed publications and various conferences.

Trial registration

18–640.

Trial registration: German Clinical Trials Register.

Registration number: DRKS00023549.

Visual attention outperforms visual-perceptual parameters required by law as an indicator of on-road driving performance

PURPOSE

A variety of visual and psychometric tests have been developed for assessing on-road driving performance and fitness to drive. The diagnostic power of a state of the art psychometric test battery (Vienna Test System) combined with a set of standard visual parameters recommended for assessing fitness to drive is investigated using an on-road driving test. The study aimed to determine whether a psychometric test battery could predict older adults' on-road driving performance. The relevance of visual standards required by law is discussed.

METHODS

Vision impairment is more prevalent in later adulthood and many studies on visual and cognitive impact on driving safety and performance therefore focus on adults above 60 years of age. We therefore acquired an extensive set of driving-related visual and psychometric performance parameters in a group of elderly drivers (N = 84, median age 69, SD 6.6 years). Visual assessment included foveal acuity, perimetric field size, and dynamic aspects of peripheral vision (termed "PP") in the computer-based Vienna Test System (VTS; Schuhfried), as well as letter contrast thresholds in foveal and parafoveal vision in a separate setup. A selection of psychometric driving-aptitude tests that demonstrated the battery's capacity to predict aspects of driving performance and safety were further conducted on the VTS. Driving performance was assessed in a standardized on-road driving test. Two independent observers rated driving performance using a fixed scoring system assessing the number of driving errors in pre-defined traffic situations. In addition, globalized driving competence scores were assigned on a 6-point scale.

RESULTS

The test battery performed excellent in identification of good drivers but failed in the prediction of bad driving performance. Visual performance indicators required by German law were less indicative of driving ability than psychometric assessment. Selective and divided attention turned out to be much more important for predicting fitness to drive than either visual acuity, size of the visual field, or contrast sensitivity.

CONCLUSION

Predicting fitness to drive by means of visual and psychometric tests is an ambitious challenge. On the one hand sensitivity of a multi-disciplinary test-battery is too low to predict reliable driving ability in diagnostic settings which require an unambiguous interpretation of test results for individual drivers. Low sensitivity and low predictive values are incompatible with that objective. On the other hand, the results are valuable for a routine screening of fitness to drive. For that case, the assessment of attentional abilities in particular appears to be promising. Performance measures of divided and selective attention showed themselves to be the most predictive for fitness to drive in a sample pre-screened for clear visual deficits. Visual performance parameters required by law, in contrast, had no meaningful impact on driving performance, indicating a gap between mandatory regulations of state authorities and research results. Our results suggest that visual acuity tests designed for clinical diagnosis and monitoring of eye diseases should not at all be the choice for a screening of fitness to drive.

Are interventions effective at improving driving in older drivers?: A systematic review

Background

With the aging of the population, the number of older drivers is on the rise. This poses significant challenges for public health initiatives, as older drivers have a relatively higher risk for collisions. While many studies focus on developing screening tools to identify medically at-risk drivers, little research has been done to develop training programs or interventions to promote, maintain or enhance driving-related abilities among healthy individuals. The purpose of this systematic review is to synopsize the current literature on interventions that are tailored to improve driving in older healthy individuals by working on components of safe driving such as: self-awareness, knowledge, behaviour, skills and/or reducing crash/collision rates in healthy older drivers.

Methods

Relevant databases such as Scopus and PubMed databases were selected and searched for primary articles published in between January 2007 and December 2017. Articles were identified using MeSH search terms: (“safety” OR “education” OR “training” OR “driving” OR “simulator” OR “program” OR “countermeasures”) AND (“older drivers” OR “senior drivers” OR “aged drivers” OR “elderly drivers”). All retrieved abstracts were reviewed, and full texts printed if deemed relevant.

Results

Twenty-five (25) articles were classified according to: 1) Classroom settings; 2) Computer-based training for cognitive or visual processing; 3) Physical training; 4) In-simulator training; 5) On-road training; and 6) Mixed interventions. Results show that different types of approaches have been successful in improving specific driving skills and/or behaviours. However, there are clear discrepancies on how driving performance/behaviours are evaluated between studies, both in terms of methods or dependent variables, it is therefore difficult to make direct comparisons between these studies.

Conclusions

This review identified strong study projects, effective at improving older drivers’ performance and thus allowed to highlight potential interventions that can be used to maintain or improve older drivers’ safety behind the wheel. There is a need to further test these interventions by combining them and determining their effectiveness at improving driving performance.

Mapping the knowledge domain of road safety studies: A scientometric analysis

As a way of obtaining a visual expression of knowledge, mapping knowledge domain (MKD) provides a vision-based analytic approach to scientometric analysis which can be used to reveal an academic community, the structure of its networks, and the dynamic development of a discipline. This study, based on the Science Citation Index Expanded (SCIE) and Social Sciences Citation Index (SSCI) articles on road safety, employs the bibliometric tools VOSviewer and CitNetExplorer to create maps of author co-citation, document co-citation, citation networks, analyze the core authors and classic documents supporting road safety studies and show the citation context and development of such studies. It shows that road safety studies clustered mainly into four groups, whose we will refer to as "effects of driving psychology and behavior on road safety", "causation, frequency and injury severity analysis of road crashes", "epidemiology, assessment and prevention of road traffic injury", and "effects of driver risk factors on driver performance and road safety", respectively. Through our analysis, the core publications and their citation relationships were quickly located and explored, and "crash frequency modeling analysis" has been identified to be the core research topic in road safety studies, with spatial statistical analysis technique emerging as a frontier of this topic.

Driving and Alzheimer's disease: A neuropsychological screening battery for the elderly

As life expectancy increases, there is a marked increase in the elderly population eager to continue driving. A large proportion of these elderly drive safely, however, patients with mild dementia are high-risk drivers.

Visual Field Impairment and Driver Fitness: A 1-Year Review of Crashes and Traffic Violations

IMPORTANCE

Occupational therapists frequently assess the fitness to drive of people with visual field impairment, but the relationship between these assessments and driving performance over time is not well understood.

OBJECTIVE

To determine traffic violation and crash incidence over a 1-yr period for drivers with visual field impairment.

DESIGN

Retrospective review of medical and driving records.

SETTING

British Columbia, Canada.

PARTICIPANTS

Participants (N = 445) were ages 26-74 yr with binocular, corrected visual acuity of ≥20/50. Goldmann visual field tests were reviewed to stratify participants on the basis of visual field impairment and whether impairments exceeded licensing standards.

OUTCOME AND MEASURES

Traffic records were reviewed to determine group-specific traffic violations and crash incidence during the year after the visual field test.

RESULTS

Of 445 participants, 292 held a valid driver's license during the designated period. Participants not meeting the licensing standards were less likely to become licensed than participants who met the standards. The results indicate that drivers with visual field impairment did not have a higher probability of crashes or violations than drivers without visual field impairment.

CONCLUSION

Drivers with visual field impairment who retained a driver's license did not have an increased probability of crashes in the following year. A larger, prospective, mixed methods study of long-term driving behaviors among people with visual field impairment is recommended.

WHAT THIS ARTICLE ADDS

This study provides preliminary data on the 1-yr incidence of traffic violations and crashes among people with visual field impairment.

When should the driver with a history of substance misuse be allowed to return to the wheel? A review of the substance misuse section of the Australian national guidelines

Assessing fitness to drive in applicants with a historical or current substance use disorder presents a specific clinical challenge. The Australian guidelines require evidence of remission and absence of cognitive change when considering applications for re-licensing driver or individuals applying to reengage in safety-sensitive work. This paper reviews some of the clinical and biochemical indicators that determine whether a particular person is in 'remission' and meets the criteria for return to driving or other safety-sensitive occupation. It provides an overview of the challenges in establishing an evidence-based approach to determining fitness for safety critical activities. There is no internationally accepted definition of 'remission'. Review of the literature and examination of assessment protocols from other national jurisdictions are available for alcohol and the more important drugs of interest in road safety. Assessing fitness to drive when there is a history of substance misuse and/or substance use disorders is a complex issue that requires assessment of biomarkers, clinical findings and clinical assessment before the person returns to driving. We propose that hair testing provides a reliable and reproducible way to demonstrate remission and provide cost-effective monitoring. Standardised psychological tests could provide a reproducible assessment of the cognitive effects of drug use and suitability to resume driving. We recommend that AustRoads amend the national guidelines to reflect an evidence-based approach to assessing fitness to drive after conviction for offences related to alcohol and drug use.

Driving in the elderly in health and disease

Driving is a complex, multifaceted instrumental activity of daily living that has an independent influence on multiple health and well-being outcomes among older adults. Therefore, the benefits of driving to the individual must be balanced, through careful assessment and diagnosis, with the potential risk to self and others posed by a medically impaired driver. The influence of dementia changes substantially during the disease progression from very mild to mild, and driving is not advised for those who have progressed to the moderate stage of Alzheimer disease. Fortunately, validated high-quality screening instruments, including modern simulators and other technology aids, can help clinicians trichotomize risk (i.e., high, moderate, or low) and determine which patients need further evaluation by a driving specialist (e.g., those in the moderate range). Moreover, a body of evidence is building regarding the efficacy of certain intervention pathways to maintain current levels of driving performance among individuals with dementia, or at least slow its decline. Even with the progression of advanced driving technologies, understanding driving ability of patients with dementia will remain a critical challenge to clinicians for the foreseeable future.

Differential Contributions of Selective Attention and Sensory Integration to Driving Performance in Healthy Aging and Alzheimer's Disease

OBJECTIVES

Patients with Alzheimer's disease (AD) demonstrate deficits in cross-cortical feature binding distinct from age-related changes in selective attention. This may have consequences for driving performance given its demands on multisensory integration. We examined the relationship of visuospatial search and binding to driving in patients with early AD and elderly controls (EC).

METHODS

Participants (42 AD; 37 EC) completed search tasks requiring either luminance-motion (L-M) or color-motion (C-M) binding, analogs of within and across visual processing stream binding, respectively. Standardized road test (RIRT) and naturalistic driving data (CDAS) were collected alongside clinical screening measures.

RESULTS

Patients performed worse than controls on most cognitive and driving indices. Visual search and clinical measures were differentially related to driving behavior across groups. L-M search and Trail Making Test (TMT-B) were associated with RIRT performance in controls, while C-M binding, TMT-B errors, and Clock Drawing correlated with CDAS performance in patients. After controlling for demographic and clinical predictors, L-M reaction time significantly predicted RIRT performance in controls. In patients, C-M binding made significant contributions to CDAS above and beyond demographic and clinical predictors. RIRT and C-M binding measures accounted for 51% of variance in CDAS performance in patients.

CONCLUSIONS

Whereas selective attention is associated with driving behavior in EC, cross-cortical binding appears most sensitive to driving in AD. This latter relationship may emerge only in naturalistic settings, which better reflect patients' driving behavior. Visual integration may offer distinct insights into driving behavior, and thus has important implications for assessing driving competency in early AD. (JINS, 2018, 24, 486-497).

Errors versus speed on the trail making test: Relevance to driving performance

BACKGROUND/OBJECTIVES

Many studies have demonstrated that speed to complete items on the Trail Making Tests (TMT A and TMT B) is useful in the prediction of driving safety. However, there is no consensus regarding optimal "cut scores" to discriminate between safe and unsafe drivers. In this study, we examine TMT speed and errors in drivers referred for a road test.

DESIGN

Retrospective analysis.

SETTING

Patients referred for a DriveWise® evaluation at Beth Israel Deaconess Medical Center in Boston, Massachusetts.

PARTICIPANTS

Drivers age 65 or older were included (total n = 373). Forty-five percent of the sample had been diagnosed with Cognitive Impairment (CI) whereas the remaining participants were in the No Cognitive Impairment (NCI) group.

MEASUREMENTS

TMT Parts A & B, Folstein Mini Mental Status Examination, Washington University Road Test.

RESULTS

CI drivers with TMT A speed exceeding 46 s were more likely to fail the road test whereas TMT B speed was not a sensitive metric in this group. In the No Cognitive Impairment (NCI) group, TMT B speed exceeding 131 s predicted driving impairment whereas TMT A speed was not sensitive. Error scores were not useful in the determination of driving fitness for either group.

CONCLUSIONS

This study provides useful criteria for health providers working with older people in the determination of driving fitness. Results suggest that TMT speed, but not error rate, is associated with road test performance. Based on our work, we advocate that pre-existing dementia should be taken into consideration when using TMT performance as a screen for driving.

Transportation and Aging: An Updated Research Agenda for Advancing Safe Mobility

This article discusses what is currently known about three important topics related to older driver safety and mobility: screening and evaluation, education and training interventions, and in-vehicle technology. Progress is being made to improve the safe mobility of older adults in these key areas; however, significant research gaps remain. This article advances the state of knowledge by identifying these gaps, and proposing further research topics will improve the lives of older adults. In addition, we discuss several themes that emerged from the review, including the need for multidisciplinary, community-wide solutions; large-scale, longitudinal studies; improved education/training for both older adults themselves and the variety of stakeholders involved in older adult transportation; and programs and interventions that are flexible and responsive to individual needs and differences.

Driving simulator scenarios and measures to faithfully evaluate risky driving behavior: A comparative study of different driver age groups

To investigate the links between mental workload, age and risky driving, a cross-sectional study was conducted on a driving simulator using several established and some novel measures of driving ability and scenarios of varying complexity. A sample of 115 drivers was divided into three age and experience groups: young inexperienced (18-21 years old), adult experienced (25-55 years old) and older adult (70-86 years old). Participants were tested on three different scenarios varying in mental workload from low to high. Additionally, to gain a better understanding of individuals' ability to capture and integrate relevant information in a highly complex visual environment, the participants' perceptual-cognitive capacity was evaluated using 3-dimensional multiple object tracking (3D-MOT). Results indicate moderate scenario complexity as the best suited to highlight well-documented differences in driving ability between age groups and to elicit naturalistic driving behavior. Furthermore, several of the novel driving measures were shown to provide useful, non-redundant information about driving behavior, complementing more established measures. Finally, 3D-MOT was demonstrated to be an effective predictor of elevated crash risk as well as decreased naturally-adopted mean driving speed, particularly among older adults. In sum, the present experiment demonstrates that in cases of either extreme high or low task demands, drivers can become overloaded or under aroused and thus task measures may lose sensitivity. Moreover, insights from the present study should inform methodological considerations for future driving simulator research. Importantly, future research should continue to investigate the predictive utility of perceptual-cognitive tests in the domain of driving risk assessment.

Association between Sleep Disordered Breathing and Nighttime Driving Performance in Mild Cognitive Impairment

OBJECTIVES

The effect of sleep disordered breathing (SDB) on driving performance in older adults has not been extensively investigated, especially in those with mild cognitive impairment (MCI). The aim of this study was to examine the relationship between severity measures of SDB and a simulated driving task in older adults with and without MCI.

METHODS

Nineteen older adults (age ≥50) meeting criteria for MCI and 23 age-matched cognitively intact controls underwent neuropsychological assessment and a driving simulator task in the evening before a diagnostic sleep study.

RESULTS

There were no differences in driving simulator performance or SDB severity between the two groups. In patients with MCI, a higher oxygen desaturation index (ODI) was associated with an increased number of crashes on the simulator task, as well as other driving parameters such as steering and speed deviation. Poorer driving performance was also associated with poorer executive functioning (set-shifting) but the relationship between ODI and crashes was independent of executive ability.

CONCLUSIONS

While driving ability did not differ between older adults with and without MCI, oxygen saturation dips in MCI were related to worse driving performance. These results suggest that decreased brain integrity may render those with SDB particularly vulnerable to driving accidents. In older adults, both cognition and SDB need to be considered concurrently in relation to driving ability. (JINS, 2017, 23, 502-510).

Using Serial Trichotomization With Common Cognitive Tests to Screen for Fitness to Drive

OBJECTIVE

The aim of this study was to illustrate the use of serial trichotomization with five common tests of cognition to achieve greater precision in screening for fitness to drive.

METHOD

We collected data (using the Montreal Cognitive Assessment, Motor-Free Visual Perception Test, Clock-Drawing Test, Trail Making Test Part A and B [Trails B], and an on-road driving test) from 83 people referred for a driving evaluation. We identified cutpoints for 100% sensitivity and specificity for each test; the driving test was the gold standard. Using serial trichotomization, we classified drivers as either "Pass," "Fail," or "Indeterminate."

RESULTS

Trails B had the best sensitivity and specificity (66.3% of participants correctly classified). After applying serial trichotomization, we correctly identified the driving test outcome for 78.3% of participants.

CONCLUSION

A screening strategy using serial trichotomization of multiple test results may reduce uncertainty about fitness to drive.

Older Adults with Mild Cognitive Impairments Show Less Driving Errors after a Multiple Sessions Simulator Training Program but Do Not Exhibit Long Term Retention

The driving performance of individuals with mild cognitive impairment (MCI) is suboptimal when compared to healthy older adults. It is expected that the driving will worsen with the progression of the cognitive decline and thus, whether or not these individuals should continue to drive is a matter of debate. The aim of the study was to provide support to the claim that individuals with MCI can benefit from a training program and improve their overall driving performance in a driving simulator. Fifteen older drivers with MCI participated in five training sessions in a simulator (over a 21-day period) and in a 6-month recall session. During training, they received automated auditory feedback on their performance when an error was noted about various maneuvers known to be suboptimal in MCI individuals (for instance, weaving, omitting to indicate a lane change, to verify a blind spot, or to engage in a visual search before crossing an intersection). The number of errors was compiled for eight different maneuvers for all sessions. For the initial five sessions, a gradual and significant decrease in the number of errors was observed, indicating learning and safer driving. The level of performance, however, was not maintained at the 6-month recall session. Nevertheless, the initial learning observed opens up possibilities to undertake more regular interventions to maintain driving skills and safe driving in MCI individuals.

Comparing Cognitive Profiles of Licensed Drivers with Mild Alzheimer's Disease and Mild Dementia with Lewy Bodies

Purpose. Alzheimer's disease (AD) and dementia with Lewy Bodies (DLB) constitute two of the most common forms of dementia in North America. Driving is a primary means of mobility among older adults and the risk of dementia increases with advanced age. The purpose of this paper is to describe the cognitive profile of licensed drivers with mild AD and mild DLB. Method. Licensed drivers with mild AD, mild DLB, and healthy controls completed neuropsychological tests measuring general cognition, attention, visuospatial/perception, language, and cognitive fluctuations. Results. The results showed differences between healthy controls and demented participants on almost all neuropsychological measures. Participants with early DLB were found to perform significantly worse on some measures of attention and visuospatial functioning in comparison with early AD. Discussion. Future research should examine the relationship between neuropsychological measures and driving outcomes among individuals with mild AD and mild DLB.

Assessment of Drivers with Alzheimer's Disease in High Demand Driving Situations: Coping with Intersections in a Driving Simulator

Intersections are one of the most complex and cognitively demanding driving situations. Individuals with dementia and, more precisely, Alzheimer's disease (AD), may face additional challenges negotiating intersections given the nature of their cognitive decline, which often includes deficits of attention. We developed a comprehensive evaluation scheme to assess simulated driving performance at intersections. The evaluation scheme captured all types of errors that could occur during preparation (i.e., prior to the intersection), execution (i.e., during the intersection), and recovery (i.e., after the intersection). Using the evaluation scheme, intersection behaviour in a driving simulator among 17 drivers with mild AD was compared to that of 21 healthy controls. The results indicated that across all types of intersections, mild AD drivers exhibited a greater number of errors relative to controls. Drivers with mild AD made the most errors during the preparation period leading up to the intersection. These findings present a novel approach to analyzing intersection behaviour and contribute to the growing body of research on dementia and driving.

Cognitive Performance, Driving Behavior, and Attitudes over Time in Older Adults

We hypothesized that changes over time in cognitive performance are associated with changes in driver perceptions, attitudes, and self-regulatory behaviors among older adults. Healthy older adults (n = 928) underwent cognitive assessments at baseline with two subsequent annual follow-ups, and completed scales regarding their perceptions, attitudes, and driving behaviours. Multivariate analysis showed small but statistically significant relationships between the cognitive tests and self-report measures, with the largest magnitudes between scores on the Trails B cognitive task (seconds), perceptions of driving abilities (β = -0.32), and situational driving avoidance (β = 0.55) (p < 0.05). Cognitive slowing and executive dysfunction appear to be associated with modestly lower perceived driving abilities and more avoidance of driving situations over time in this exploratory analysis.

Deficits in Attention and Visual Processing but not Global Cognition Predict Simulated Driving Errors in Drivers Diagnosed With Mild Alzheimer's Disease

This study sought to predict driving performance of drivers with Alzheimer's disease (AD) using measures of attention, visual processing, and global cognition. Simulated driving performance of individuals with mild AD (n = 20) was contrasted with performance of a group of healthy controls (n = 21). Performance on measures of global cognitive function and specific tests of attention and visual processing were examined in relation to simulated driving performance. Strong associations were observed between measures of attention, notably the Test of Everyday Attention (sustained attention; r = -.651, P = .002) and the Useful Field of View (r = .563, P = .010), and driving performance among drivers with mild AD. The Visual Object and Space Perception Test-object was significantly correlated with the occurrence of crashes (r = .652, P = .002). Tests of global cognition did not correlate with simulated driving outcomes. The results suggest that professionals exercise caution when extrapolating driving performance based on global cognitive indicators.

Clinician Effectiveness in Assessing Fitness to Drive of Medically At-Risk Older Adults

OBJECTIVES

To model the relative contributions of driver data and clinical judgments to clinical ratings of driver capability for a state licensing authority and to compare ratings with on-road test results.

DESIGN

Retrospective, logistic regression.

SETTING

Missouri Driver License Bureau.

PARTICIPANTS

Adults aged 60 and older (N = 652; 52% male) evaluated by a physician of their choosing and a portion subsequently road tested (n = 286).

MEASUREMENTS

Clinical data from an evidence-based physician statement (Form 1528). A three-level rating (likely capable, unclear, not capable) was collapsed into two outcomes (0 likely capable; 1 unclear, not capable) as the dependent variable. Independent variables (predictors) were age, sex, driving exposure, recent crash or police action, number of medical conditions, medication side effects, driver insight, and disease functional severity rating for driving.

RESULTS

Three variables in the model (Nagelkerke coefficient of determination = 0.64; P < .001) were significant in the expected direction: disease functional severity for driving (odds ratio (OR = 6.65), insight (OR = 2.35), and age (OR = 1.06). Proportionately more drivers rated likely capable (73%) passed the road test than those rated unclear or not capable (62%).

CONCLUSION

Judgments of disease severity, decrements in driver insight, and older age influenced clinician ratings of driving capability. Correspondence of physician ratings to on-road test outcomes was imperfect, highlighting the complexities in translation of clinical judgments to on-road performance. Both means of assessment have important and additive roles in driver licensing.

Advice for Elderly Drivers in a German Memory Clinic: A Case Report on Medical, Ethical and Legal Consequences

We report on a 75-year-old female who consulted our Memory Clinic because of subjective memory complaints that she first recognized three months previously. Next to the standard detailed patient history, neuropsychological assessment, psychopathological status, the patient's driving history played an important role in the diagnostic process. In this case report, we illustrate the diagnostic process starting with the first consultation, including a short neuropsychological examination and communicating its results, reporting on further work-up (detailed neuropsychological assessment, MRI scan and cerebrospinal fluid (CSF) analysis) up to the final consultation, including advice for the patient. We will focus on several medical, ethical and legal difficulties that may occur when consulting elderly drivers with initial cognitive decline.

Assessment tools predicting fitness to drive in older adults: a systematic review

This systematic review synthesizes the research on screening and assessment tools used to determine older adults' fitness to drive. After a comprehensive search of the literature targeting tools commonly used by occupational therapists, 64 studies were reviewed and synthesized. The evidence demonstrated that a single tool measuring cognition, vision, perception, or physical ability individually is not sufficient to determine fitness to drive. Although some tools have stronger evidence than others, this review supports using different and focused assessment tools together for specific medical conditions. Results indicate that behind-the-wheel assessment remains the gold standard for driving evaluation; however, emerging evidence for observation of complex instrumental tasks of daily living and driving simulation supports further investigation with these tools.

Driving Competence in Mild Dementia with Lewy Bodies: In Search of Cognitive Predictors Using Driving Simulation

Driving is a multifactorial behaviour drawing on multiple cognitive, sensory, and physical systems. Dementia is a progressive and degenerative neurological condition that impacts the cognitive processes necessary for safe driving. While a number of studies have examined driving among individuals with Alzheimer's disease, less is known about the impact of Dementia with Lewy Bodies (DLB) on driving safety. The present study compared simulated driving performance of 15 older drivers with mild DLB with that of 21 neurologically healthy control drivers. DLB drivers showed poorer performance on all indicators of simulated driving including an increased number of collisions in the simulator and poorer composite indicators of overall driving performance. A measure of global cognitive function (i.e., the Mini Mental State Exam) was found to be related to the overall driving performance. In addition, measures of attention (i.e., Useful Field of View, UFOV) and space processing (Visual Object and Space Perception, VOSP, Test) correlated significantly with a rater's assessment of driving performance.

Consensus statements for screening and assessment tools

Occupational therapists, both generalists and specialists, have a critical role in providing services to senior drivers. These services include evaluating fitness-to-drive, developing interventions to support community mobility, and facilitating the transition from driving to non-driving when necessary for personal and community safety. The evaluation component and decision-making process about fitness-to-drive are highly dependent on the use of screening and assessment tools. The purpose of this paper is to briefly present the rationale and context for 12 consensus statements about the usefulness and appropriateness of screening and assessment tools to determine fitness-to-drive, within the occupational therapy clinical setting, and their implications on community mobility.

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 attention deficit hyperactivity disorder

Adults with attention deficit hyperactivity disorder (ADHD) suffer from various impairments of cognitive, emotional and social functioning, which can have considerable consequences for many areas of daily living. One of those areas is driving a vehicle. Driving is an important activity of everyday life and requires an efficient interplay between multiple cognitive, perceptual, and motor skills. In the present study, a selective review of the literature on driving-related difficulties associated with ADHD is performed, seeking to answer whether individuals with ADHD show increased levels of unsafe driving behaviours, which cognitive (dys)functions of individuals with ADHD are related to driving difficulty, and whether pharmacological treatment significantly improves the driving behaviour of individuals with ADHD. The available research provides convincing evidence that individuals with ADHD have different and more adverse driving outcomes than individuals without the condition. However, it appears that not all individuals with ADHD are affected uniformly. Despite various cognitive functions being related with driving difficulties, these functions do not appear helpful in detecting high risk drivers with ADHD, nor in predicting driving outcomes in individuals with ADHD, since impairments in these functions are defining criteria for the diagnoses of ADHD (e.g., inattention and impulsivity). Pharmacological treatment of ADHD, in particular stimulant drug treatment, appears to be beneficial to the driving difficulties experienced by individuals with ADHD. However, additional research is needed, in particular further studies that address the numerous methodological weaknesses of many of the previous studies.

Typical Brake Reaction Times Across the Life Span

This paper provides average brake reaction times for healthy community living adults from 16 to 90+ years of age, divided by gender. Using consistent directions and context, the RT-2S Simple Brake Reaction shows that average brake reactions for males is 0.50 seconds (median = 0.48, minimum = 0.25 maximum = 0.92) and for females is 0.53 seconds (median = 0.51 minimum = 0.30 maximum = 1.36). The use of a brake reaction timer to assess fitness to drive may be useful for clients recovering from orthopedic surgery, while use as a driving determinate of older adults should be done in conjunction with other tools.

Crash avoidance in response to challenging driving events: The roles of age, serialization, and driving simulator platform

We examined the crash avoidance behaviors of older and middle-aged drivers in reaction to six simulated challenging road events using two different driving simulator platforms. Thirty-five healthy adults aged 21-36 years old (M=28.9±3.96) and 35 healthy adults aged 65-83 years old (M=72.1±4.34) were tested using a mid-level simulator, and 27 adults aged 21-38 years old (M=28.6±6.63) and 27 healthy adults aged 65-83 years old (M=72.7±5.39) were tested on a low-cost desktop simulator. Participants completed a set of six challenging events varying in terms of the maneuvers required, avoiding space given, directional avoidance cues, and time pressure. Results indicated that older drivers showed higher crash risk when events required multiple synchronized reactions. In situations that required simultaneous use of steering and braking, older adults tended to crash significantly more frequently. As for middle-aged drivers, their crashes were attributable to faster driving speed. The same age-related driving patterns were observed across simulator platforms. Our findings support the hypothesis that older adults tend to react serially while engaging in cognitively challenging road maneuvers.

Effects of Different Types of Cognitive Training on Cognitive Function, Brain Structure, and Driving Safety in Senior Daily Drivers: A Pilot Study

Background. Increasing proportion of the elderly in the driving population raises the importance of assuring their safety. We explored the effects of three different types of cognitive training on the cognitive function, brain structure, and driving safety of the elderly. Methods. Thirty-seven healthy elderly daily drivers were randomly assigned to one of three training groups: Group V trained in a vehicle with a newly developed onboard cognitive training program, Group P trained with a similar program but on a personal computer, and Group C trained to solve a crossword puzzle. Before and after the 8-week training period, they underwent neuropsychological tests, structural brain magnetic resonance imaging, and driving safety tests. Results. For cognitive function, only Group V showed significant improvements in processing speed and working memory. For driving safety, Group V showed significant improvements both in the driving aptitude test and in the on-road evaluations. Group P showed no significant improvements in either test, and Group C showed significant improvements in the driving aptitude but not in the on-road evaluations. Conclusion. The results support the effectiveness of the onboard training program in enhancing the elderly's abilities to drive safely and the potential advantages of a multimodal training approach.

Predicting road test performance in drivers with stroke

OBJECTIVE. The aim of this study was to develop a brief screening battery to predict the on-road performance of drivers who had experienced a stroke. METHOD. We examined 72 people with stroke referred by community physicians to an academic rehabilitation center. The outcome variable was pass or fail on the modified Washington University Road Test. Predictor measures were tests of visual, motor, and cognitive functioning. RESULTS. The best predictive model for failure on the road test included Trail Making Test Part A and the Snellgrove Maze Task(®). CONCLUSION. A screening battery that can be performed in less than 5 min was able to assist in the prediction of road test performance in a sample of drivers with stroke. A probability of failure calculator may be useful for clinicians in their decision to refer clients with stroke for a comprehensive driving evaluation.

How to report and interpret screening test properties: guidelines for driving researchers

One important goal of driving research is the development of a short but valid office-based screening test for fitness to drive of aging drivers. Several candidate tests have been proposed already, and no doubt others will be proposed in the future. It might seem obvious that authors advocating for the adoption of a particular screening test or procedure should report sensitivity, specificity, and other common screening test properties. Unfortunately, driving researchers have frequently failed to report any screening test properties. Others have reported screening test properties but have made basic mistakes such as calculating predictive values of positive and negative tests but reporting them incorrectly as sensitivity and specificity. These omissions and errors suggest that some driving researchers may be unaware of the importance of accurately reporting test properties when proposing a screening procedure and that others may need a refresher on how to calculate and interpret the most common screening test properties. Many good learning resources for screening and diagnostic tests are available, but most of them are intended for students and researchers in medicine, epidemiology, or public health. We hope that this tutorial in a prominent transportation journal will help lead to improved reporting and interpretation of screening test properties in articles that assess the usefulness of potential screening tools for fitness to drive.

Determining the validity of the AMA guide: A historical cohort analysis of the assessment of driving related skills and crash rate among older drivers

BACKGROUND

Chronic health conditions associated with ageing can lead to changes in driving ability. The Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive II) is a 5-year prospective study funded by the Canadian Institutes of Health Research aiming to develop an in-office screening tool that will help clinicians identify potentially at-risk older drivers. Currently, no tools exist to directly predict the risk of motor vehicle collision (MVC) in this population. The American Medical Association (AMA), in collaboration with the National Highway Traffic Safety Association, has designed an opinion-based guide for assessing medical fitness to drive in older adults and recommends that physicians use the Assessment of Driving Related Skills (ADReS) as a test battery to measure vision, cognition and motor/somatosensory functions related to driving. The ADReS consists of the Snellen visual acuity test, visual fields by confrontation test, Trail Making Test part B, clock drawing test, Rapid Pace Walk, and manual tests of range of motion and motor strength. We used baseline data from the Candrive/Ozcandrive common cohort of older drivers to evaluate the validity of the ADReS subtests. We hypothesized that participants who crashed in the 2 years before the baseline assessment would have poorer scores on the ADReS subtests than participants who had not crashed.

METHODS

In the Candrive/Ozcandrive study, 1230 participants aged 70 years or older were recruited from 7 Canadian cities, 1 Australian city and 1 New Zealand city, all of whom completed a comprehensive clinical assessment at study entry. The assessment included all tests selected as part of the ADReS. For this historical cohort study, data on all crashes (at-fault and non-at-fault) that occurred within 2 years preceding the baseline assessment were obtained from the respective licensing jurisdictions. Those who crashed were compared to those who had not crashed on their ADReS subtest scores using Pearson's chi-squared test and Student's t-test.

RESULTS

Sixty-three of the 1230 participants (5.1%) were involved in an MVC within the 2 years preceding the baseline assessment. Contrary to our hypothesis, there were no statistically significant associations between abnormal performance on the tests constituting the ADReS and history of crash in the previous 2 years (p>0.01).

DISCUSSION

We found that a history of crash in the previous 2 years was not associated with abnormalities on the subtests comprising the ADReS. This suggests the need for prospective analyses of risk factors over time to establish sensitive, valid predictors of crash that can be incorporated in clinical practice guidelines.

It is premature to test older drivers with the SIMARD-MD

BACKGROUND

A new tool, the SIMARD-MD, has been proposed to help physicians identify cognitively impaired drivers who may be unfit to drive, but little empirical evidence is available to justify its use. We analyzed data from a cohort of older Canadian drivers who had undergone cognitive testing to: (1) correlate the SIMARD-MD with other tools that measure cognition (e.g., trail-making test), (2) identify how many drivers, using published cut-offs on the SIMARD-MD, would be recommended to lose their license, or be considered fit to drive, or be required to undergo further driving assessment, and (3) determine if the SIMARD-MD is biased by level of education as many cognitive tools are.

METHODS

Cross-sectional data from 841 drivers aged 70 and over from seven Canadian sites who are enrolled in a 5-year cohort study were used for the analyses. Scores on the SIMARD-MD were correlated with scores on the other cognitive measures. The recommendations that would be made based on the SIMARD-MD scores were based on published cut-off values suggested by the authors of the tool. The impact of education status was examined using linear regression controlling for age.

RESULTS

Correlations between the SIMARD-MD and other cognitive measures ranged from .15 to .86. Using published cut-off scores, 21 participants (2.5%) would have been recommended to relinquish their licenses, 428 (50.9%) would have been deemed fit to drive, and 392 (46.6%) would have been required to undergo further testing. We found a difference of 8.19 points (95% CI=4.99, 11.40, p<.001) in favor of drivers with post-secondary education versus those without, representing over 11% of the mean score.

DISCUSSION

The SIMARD-MD is unlikely to be valuable to clinicians because it lacks sufficient precision to provide clear recommendations about fitness-to-drive. Recommendations based solely on the SIMARD-MD may place many seniors at risk of losing their transportation mobility or incurring unnecessary stress and costs to prove they are safe to drive. Furthermore, the education bias may create an unwanted structural inequity. Hence, adoption of the SIMARD-MD as a tool to determine fitness-to-drive appears premature.

Clock drawing as a screen for impaired driving in aging and dementia: is it worth the time?

Clock drawing is recommended by medical and transportation authorities as a screening test for unsafe drivers. The objective of the present study was to assess the usefulness of different clock drawing systems as screening measures of driving performance in 122 healthy and cognitively impaired older drivers. Clock drawing was measured using four different scoring systems. Driving outcomes included global ratings of safety and the error rate on a standardized on-road test. Findings revealed that clock drawing was significantly correlated with the driving score on the road test for each of the scoring systems. However, receiver operator curve analyses showed limited clinical utility for clock drawing as a screening instrument for impaired on-road driving performance with the area under the curve ranging from 0.53 to 0.61. Results from this study indicate that clock drawing has limited utility as a solitary screening measure of on-road driving, even when considering a variety of scoring approaches.

Can we improve clinical prediction of at-risk older drivers?

OBJECTIVES

To conduct a pilot study to evaluate the predictive value of the Montreal Cognitive Assessment test (MoCA) and a brief test of multiple object tracking (MOT) relative to other tests of cognition and attention in identifying at-risk older drivers, and to determine which combination of tests provided the best overall prediction.

METHODS

Forty-seven currently licensed drivers (58-95 years), primarily from a clinical driving evaluation program, participated. Their performance was measured on: (1) a screening test battery, comprising MoCA, MOT, Mini-Mental State Examination (MMSE), Trail-Making Test, visual acuity, contrast sensitivity, and Useful Field of View (UFOV) and (2) a standardized road test.

RESULTS

Eighteen participants were rated at-risk on the road test. UFOV subtest 2 was the best single predictor with an area under the curve (AUC) of .84. Neither MoCA nor MOT was a better predictor of the at-risk outcome than either MMSE or UFOV, respectively. The best four-test combination (MMSE, UFOV subtest 2, visual acuity and contrast sensitivity) was able to identify at-risk drivers with 95% specificity and 80% sensitivity (.91 AUC).

CONCLUSIONS

Although the best four-test combination was much better than a single test in identifying at-risk drivers, there is still much work to do in this field to establish test batteries that have both high sensitivity and specificity.

How effective is the Trail Making Test (Parts A and B) in identifying cognitively impaired drivers?

BACKGROUND

the medical community plays an important role in identifying drivers who may no longer be competent to drive due to illnesses such as dementia. Several office-based cognitive screening tools are currently used by the medical community, e.g. Mini-Mental State Examination, Trail Making Test (TMT), to assist in the identification of cognitively impaired (CI) at-risk drivers. However, the predictive validity of these tools is questionable.

OBJECTIVE

to examine the predictive power of the TMT for on-road driving performance.

METHODS

data from a prospective sample of CI and healthy older drivers were collected. TMT-A and -B (time and errors) served as predictor variables, with pass/fail on a scientifically based on-road assessment used as the criterion variable. Receiver operating characteristic (ROC) curve analysis was used to assess overall 'diagnostic' accuracy of TMT-A and -B for driving competency. Cut points from previous studies/guidelines were used to assess predictive power.

FINDINGS

a total of 134 older drivers (mean age = 75.30; SD = 7.83) participated: 87 healthy controls and 47 CI individuals. All predictor variables, with the exception of TMT-A errors, were significantly correlated with driving outcome. However, results from ROC curve analyses indicated that only TMT-A and -B total time had moderate discriminative abilities. Results also indicate that the power of the TMT is the lowest where physicians need it most (e.g. identifying CI patients whose driving skills have declined to an unsafe level).

CONCLUSION

TMT-A and -B outcomes are most likely to be inaccurate in those whose driving competency has declined to an unsafe level, resulting in risks to both individual and public safety.

Driving Assessment Tools Used by Driver Rehabilitation Specialists: Survey of Use and Implications for Practice

OBJECTIVE. This article describes the use of assessment tools by North American driver rehabilitation specialists (DRSs).

PARTICIPANTS. Participants were 227 self-identified DRSs from the combined databases of two national associations.

MEASURES. Information was solicited through a self-administered survey about the driving evaluation process, assessment tools, and process for making fitness-to-drive recommendations.

RESULTS. More than 80% of the DRSs reported testing visual acuity, range of motion, muscle strength, and fine motor coordination. The most consistently used cognitive–perceptual tests were the Trail Making Tests, Motor-Free Visual Perception Test–Revised, and short cognitive screening tests. A client’s behind-the-wheel performance was the main factor in making a fitness-to-drive recommendation. Few specialists are using computer-based tests or interactive driving simulators.

CONCLUSION. Although use of the Useful Field of View® has increased, there continues to be no consistency in cognitive assessments or guidelines for behind-the-wheel assessment. Implications for practice are discussed.

The Introduction of a New Screening Tool for the Identification of Cognitively Impaired Medically At-Risk Drivers: The SIMARD A Modification of the DemTect

The number of drivers with a cognitive impairment due to dementia or other age-associated pathologies will increase significantly over the next 3 decades. Physicians are well placed to identify medically at-risk drivers, but are hampered by the lack of a valid, easy to administer screening tool. This research develops and validates a brief screening tool for use in the primary care setting to identify drivers with cognitive impairment with or without dementia. Initial Study Participants: A cohort of 146 consecutive referrals from community-based family physicians, diagnosed with an undifferentiated cognitive impairment or dementia, as well as 35 community dwelling healthy controls. Validation Study: A cohort of 192 consecutive referrals carrying the same diagnosis as above and 52 community dwelling healthy controls. Criterion Measure: Pass/fail on an On-Road evaluation. Predictor Measures: Subtests of the DemTect, a screening test for cognitive impairment or dementia developed by Kalbe and colleagues.(1) Initial Study: Three of the DemTect measures predicted On-Road outcomes (R(2) = .262). Regression results were used to develop a simple scoring algorithm, with cut-points then derived by identifying those most at risk for failing and passing the On-Road assessment, and those needing a driving assessment for determination of driving competency. 89 individuals scored in the indeterminate range, with 49 and 43 predicted to fail and pass, respectively-86% and 84% of those predicted to fail and pass did subsequently fail and pass. Validation Study: 123 individuals scored in the indeterminate range, with 66 and 55 predicted to fail and pass, respectively-80% and 87% of those predicted to fail and pass did subsequently fail and pass.

CONCLUSIONS

The SIMARD A Modification of the DemTect ( S creen for the I dentification of cognitively impaired M edically A t- R isk D rivers) is a brief paper and pencil screening tool with a high degree of accuracy that can be used for immediate decisions in the clinical setting.

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.