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

Post-Concussion Driving Behaviors and Opinions: A Survey of Collegiate Student-Athletes

Post-concussion driving restrictions are eminent, but we lack understanding of current behaviors and opinions about driving following concussion among populations at risk of concussion. We aimed to describe post-concussion driving behaviors and opinions among collegiate student-athletes. Student-athletes completed a survey (response rate = 45.3%, 223/492) regarding their post-concussion driving behaviors and opinions. Response frequencies and percentages are presented. Student-athletes self-reported a total of 169 lifetime concussions (0.76 ± 1.02 each). Of the 169 concussions, 52.1% (88/169) were diagnosed and 52.7% (89/169) occurred while the student-athlete possessed a valid driver's license. Student-athletes refrained from driving following 43.8% (39/89) of the concussive events. Student-athletes who refrained most commonly did so for only 24-48 h (20.5%, 8/39) and because a health care provider advised them to (33.3%, 13/39). Student-athletes most commonly reported that they would feel "very unsafe" driving a car immediately following injury (38.4%, 84/219). When asked whether driving restrictions would influence their decision to report the injury to a health care provider, 7.9% reported that it "definitely would" (17/214), 26.6% "probably would" (57/214), 17.8%"neutral" (38/214), 24.8% "probably would not" (53/214), and 22.9% "definitely would not" (49/214). Despite generally believing that driving immediately following a concussion is unsafe, a majority of student-athletes did not refrain from driving at any point following their previous concussions. Post-concussion driving restrictions may have some influence on student-athletes' decisions to report the injury to a health care provider. Health care providers play a critical role in post-concussion driving restriction, but lack standardized recommendations to guide their care.

Driving Cessation in Patients Attending a Young-Onset Dementia Clinic: A Retrospective Cohort Study

Background

Although driving by persons with dementia is an important public health concern, little is known about driving cessation in younger people with dementia. We aimed to determine the prevalence and factors affecting driving cessation in individuals with and without dementia aged under 65 years attending a memory clinic in a European setting.

Methods

Subjects were consecutive patients assessed at a specialist memory service at a university teaching hospital between 2000 and 2010. The data collected included demographic, clinical, standardized cognitive assessments as well as information on driving. Dementia diagnosis was made using ICD-10 criteria.

Results

Of the 225 people who were or had been drivers, 32/79 (41%) with young-onset dementia (YOD) stopped driving compared to 25/146 (17%) patients who had cognitive impairment due to other causes. Women were more likely to cease driving and voluntarily than men (p < 0.001). Diagnosis of YOD was associated with driving cessation (1.193, 95% CI 0.570–1.815, p ≤ 0.001), and was mediated by impairment in praxis with the highest indirect mediation effect (0.754, 95% CI 0.183–1.401, p = 0.009).

Conclusions

YOD diagnosis, female gender, and impairment in praxis have a higher probability for driving cessation in those under 65 years of age with cognitive impairment.

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

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

Detection of Risky Driving Behaviors in the Naturalistic Environment in Healthy Older Adults and Mild Alzheimer's Disease

Analyzing naturalistic driving behavior recorded with in-car cameras is an ecologically valid method for measuring driving errors, but it is time intensive and not easily applied on a large scale. This study validated a semi-automated, computerized method using archival naturalistic driving data collected for drivers with mild Alzheimer’s disease (AD; n = 44) and age-matched healthy controls (HC; n = 16). The computerized method flagged driving situations where safety concerns are most likely to occur (i.e., rapid stops, lane deviations, turns, and intersections). These driving epochs were manually reviewed and rated for error type and severity, if present. Ratings were made with a standardized scoring system adapted from DriveCam^®. The top eight error types were applied as features to train a logistic model tree classifier to predict diagnostic group. The sensitivity and specificity were compared among the event-based method, on-road test, and composite ratings of two weeks of recorded driving. The logistic model derived from the event-based method had the best overall accuracy (91.7%) and sensitivity (97.7%) and high specificity (75.0%) compared to the other methods. Review of driving situations where risk is highest appears to be a sensitive data reduction method for detecting cognitive impairment associated driving behaviors and may be a more cost-effective method for analyzing large volumes of naturalistic data.

The challenge of safe driving among elderly drivers

The challenge of ageing has two key aspects with regard to driving: mobility and safety. It is necessary for elderly adults to preserve independent mobility and activity; however, physical frailty and cognitive limitations have negative effects on their safety. Therefore, the issue of driving, and more specifically, the fostering of safe driving of old people, is crucial, especially due the increasing number of elderly people holding a driving license. The purpose of this Letter is to point out the complexity of elderly driving and to suggest countermeasures by acknowledging that obtaining the correct balance between safety and mobility of older drivers is a complicated and sensitive task. To address this issue, the authors suggest accommodating their driving behaviour and patterns, in light of the deteriorating driving skills, by integrating social and policy procedures and use of emerging technologies. Policy steps to support elderly drivers and their loved ones by gradually controlling driving of elderly population when this becomes risky to them may serve as a desired countermeasure according to a proved tool such as technology. Utilisation of advanced technologies can help to monitor travel and driver behaviour and ability to make the necessary alterations, based on elderly driving skills.

Saccular Impairment in Alzheimer's Disease Is Associated with Driving Difficulty

BACKGROUND/AIMS

Patients with Alzheimer's disease (AD) experience increased rates of vestibular loss. Recent studies suggest that saccular impairment in mild cognitive impairment (MCI) and AD patients is associated with impaired spatial cognitive function. However, the impact of saccular impairment on everyday behaviors that rely on spatial cognitive function is unknown.

METHODS

We recruited 60 patients (21 MCI and 39 AD) from an interdisciplinary Memory Clinic. Saccular function was measured, and a visuospatial questionnaire was administered to assess whether participants experienced impairments in terms of driving difficulty, losing objects, falls, and fear of falling.

RESULTS

In multiple logistic regression analyses, MCI and AD patients with bilateral saccular impairment had a significant, greater than 12-fold odds of driving difficulty (OR 12.1, 95% CI 1.2, 117.7) compared to MCI and AD patients with normal saccular function, and the association appears to be mediated by spatial cognition as measured by the Money Road Map Test.

CONCLUSION

This study suggests a novel link between saccular impairment and driving difficulty in MCI and AD patients and demonstrates that driving difficulty may be a real-world manifestation of impaired spatial cognition associated with saccular impairment.

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).

Driving, dementia and the Driver and Vehicle Licensing Agency: a survey of old age psychiatrists

Aims and Method

We surveyed old age psychiatrists in the north-east of England to determine what they considered relevant indicators of driving ability. The survey asked about their satisfaction with the current Driver and Vehicle Licensing Agency (DVLA) procedure of assessing competence to drive in patients with dementia and how they thought this could be improved.

Results

Fifty-seven out of 76 psychiatrists (75%) responded; 26 (45%) respondents thought the forms issued by the DVLA were unsatisfactory but 32 (57%) were satisfied with the eventual decisions made about individual patients. Factors thought to be relevant indicators of driving ability were occupational therapy (n=46, 81%), neuropsychological assessments (n=43, 75%) and carer's report of driving (n=48, 84%). Factors thought not to be relevant were patient's report of driving ability (n=13, 23%) and the Mini Mental State Examination (n=21, 38%).

Clinical Implications

The current system for determining driving ability in people with cognitive impairment and dementia was felt to be unsatisfactory. A multidisciplinary approach and use of on-road driving assessments may improve decision-making.

Electronic Medical Record Documentation of Driving Safety for Veterans with Diagnosed Dementia

OBJECTIVES

Many older adults continue to drive following dementia diagnosis, with medical providers increasingly likely to be involved in addressing such safety concerns. This study examined electronic medical record (EMR) documentation of driving safety for veterans with dementia (N = 118) seen in Veterans Affairs primary care and interdisciplinary geriatrics clinics in one geographic region over a 10-year period.

METHODS

Qualitative directed content analysis of retrospective EMR data.

RESULTS

Assessment of known risk factors or subjective concerns for unsafe driving were documented in fewer than half of observed cases; specific recommendations for driving safety were evident for a minority of patients, with formal driving evaluation the most frequently documented recommendation by providers.

CONCLUSION

Utilizing data from actual clinical encounters provides a unique snapshot of how driving risk and safety concerns are addressed for veterans with dementia. This information provides a meaningful frame of reference for understanding potential strengths and possible gaps in how this important topic area is being addressed in the course of clinical care.

CLINICAL IMPLICATIONS

The EMR is an important forum for interprofessional communication, with documentation of driving risk and safety concerns an essential element for continuity of care and ensuring consistency of information delivered to patients and caregivers.

Alzheimer's disease and driving: review of the literature and consensus guideline from Belgian dementia experts and the Belgian road safety institute endorsed by the Belgian Medical Association

Alzheimer's disease (AD) is a highly prevalent condition and its prevalence is expected to further increase due to the aging of the general population. It is obvious that the diagnosis of AD has implications for driving. Finally, driving discussions are also emotionally charged because driving is associated with independence and personal identity. However, it is not clear how to implement this in clinical practice and the Belgian law on driving is rather vague in its referral to neurodegenerative brain diseases in general nor does it provide clear-cut instructions for dementia or AD compared to for example driving for patients with epilepsy and as such does not prove to be very helpful. The present article reviews what is known from both literature and existing guidelines and proposes a consensus recommendation tailored to the Belgian situation agreed by both AD experts and the Belgian Road Safety Institute endorsed by the Belgian Medical Association. It is concluded that the decision about driving fitness should be considered as a dynamic process where the driving fitness is assessed and discussed early after diagnosis and closely monitored by the treating physician. The diagnosis of AD on itself definitely does not imply the immediate and full revocation of a driving license nor does it implicate a necessary referral for a formal on-road driving assessment. There is no evidence to recommend a reduced exposure or a mandatory co-pilot. A MMSE-based framework to trichotomise AD patients as safe, indeterminate or unsafe is presented. The final decision on driving fitness can only be made after careful history taking and clinical examination, neuropsychological, functional and behavioral evaluation and, only for selected cases, a formal assessment of driving performance.

Vestibular Dysfunction and Difficulty with Driving: Data from the 2001-2004 National Health and Nutrition Examination Surveys

BACKGROUND AND OBJECTIVE

There is growing understanding of the role of vestibular function in spatial navigation and orientation. Individuals with vestibular dysfunction demonstrate impaired performance on static and dynamic tests of spatial cognition, but there is sparse literature characterizing how these impairments might affect individuals in the real-world. Given the important role of visuospatial ability in driving a motor vehicle, we sought to evaluate whether individuals with vestibular dysfunction might have increased driving difficulty.

MATERIALS AND METHODS

We used data from the 2001-2004 National Health and Nutrition Examination Surveys to evaluate the influence of vestibular dysfunction in driving difficulty in a nationally representative sample of U.S. adults aged ≥50 years (n = 3,071). Vestibular function was measured with the modified Romberg test. Furthermore, since vestibular dysfunction is a known contributor to falls risk, we assessed whether individuals with vestibular dysfunction and concomitant driving difficulty were at an increased risk of falls.

RESULTS

In multivariate analyses, vestibular dysfunction was associated with a twofold increased odd of driving difficulty (odds ratio 2.16, 95% CI 1.57, 2.98). Among participants with vestibular dysfunction, concomitant driving difficulty predicted an increased risk of falls that was significantly higher than in participants with vestibular dysfunction only (odds ratio 13.01 vs. 2.91, p < 0.0001).

CONCLUSION

This study suggests that difficulty driving may be a real-world manifestation of impaired spatial cognition associated with vestibular loss. Moreover, driving difficulty may be a marker of more severe vestibular dysfunction.

Neuropsychological comparisons of cocaine versus methamphetamine users: A research synthesis and meta-analysis

BACKGROUND

Previous meta-analytical research examining cocaine and methamphetamine separately suggests potentially different neuropsychological profiles associated with each drug. In addition, neuroimaging studies point to distinct structural changes that might underlie differences in neuropsychological functioning.

OBJECTIVES

This meta-analysis compared the effect sizes identified in cocaine versus methamphetamine studies across 15 neuropsychological domains.

METHOD

Investigators searched and coded the literature examining the neuropsychological deficits associated with a history of either cocaine or methamphetamine use. A total of 54 cocaine and 41 methamphetamine studies were selected, yielding sample sizes of 1,718 and 1,297, respectively. Moderator analyses were conducted to compare the two drugs across each cognitive domain.

RESULTS

Data revealed significant differences between the two drugs. Specifically, studies of cocaine showed significantly larger effect-size estimates (i.e., poorer performance) in verbal working memory when compared to methamphetamine. Further, when compared to cocaine, methamphetamine studies demonstrated significantly larger effect sizes in delayed contextual verbal memory and delayed visual memory.

CONCLUSION

Overall, cocaine and methamphetamine users share similar neuropsychological profiles. However, cocaine appears to be more associated with working memory impairments, which are typically frontally mediated, while methamphetamine appears to be more associated with memory impairments that are linked with temporal and parietal lobe dysfunction.

On-road assessment of fitness-to-drive in persons with MS with cognitive impairment: A prospective study

Background:

Cognitive impairment is common in multiple sclerosis (MS). In other populations, cognitive impairment is known to affect fitness-to-drive. Few studies have focused on fitness-to-drive in MS and no studies have solely focused on the influence of cognitive impairment.

Objective:

To assess fitness-to-drive in persons with MS with cognitive impairment and low physical disability.

Methods:

Persons with MS, aged 18–59 years with EDSS ⩽ 4.0, impaired processing speed, and impairment on at least one measure of memory or executive function, were recruited. Cognition was assessed using the Minimal Assessment of Cognitive Function battery. A formal on-road driving assessment was conducted. Chi-square analysis examined the association between the fitness-to-drive (pass/fail) and the neuropsychological test results (normal/impaired). Bayesian statistics predicting failure of the on-road assessment were calculated.

Results:

Of 36 subjects, eight (22.2%) were unfit to drive. Only the BVMTR-IR, measuring visual-spatial memory, predicted on-road driving assessment failure ( X2 ( df = 1, N = 36) = 3.956; p = 0.047) with a sensitivity of 100%, but low specificity (35.7%) due to false positives (18/25).

Conclusion:

In persons with MS and impaired processing speed, impairment on the BVMTR-IR should lead clinicians to address fitness-to-drive.

Driving in mild cognitive impairment: The role of depressive symptoms

OBJECTIVES

Previous studies indicate a negative association between depression and driving fitness in the general population. Our goal was to cover a gap in the literature and to explore the link between depressive symptoms and driving behavior in individuals with mild cognitive impairment (MCI) through the use of a driving simulator experiment.

METHODS

Twenty-four individuals with MCI (mean age = 67.42, SD = 7.13) and 23 cognitively healthy individuals (mean age = 65.13, SD = 7.21) were introduced in the study. A valid driving license and regular car use served as main inclusion criteria. Data collection included a neurological/neuropsychological assessment and a driving simulator evaluation. Depressive symptomatology was assessed with the Patient Health Questionnaire (PHQ-9).

RESULTS

Significant interaction effects indicating a greater negative impact of depressive symptoms in drivers with MCI than in cognitively healthy drivers were observed in the case of various driving indexes, namely, average speed, accident risk, side bar hits, headway distance, headway distance variation, and lateral position variation. The associations between depressive symptoms and driving behavior remained significant after controlling for daytime sleepiness and cognition.

CONCLUSIONS

Depressive symptoms could be a factor explaining why certain patients with MCI present altered driving skills. Therefore, interventions for treating the depressive symptoms of individuals with MCI could prove to be beneficial regarding their driving performance.

Predictors of Postdeployment Functioning in Combat-Exposed U.S. Military Veterans

Posttraumatic stress disorder (PTSD) and sequelae of mild traumatic brain injury (mTBI) are presumed to contribute to reintegration difficulties in combat-exposed veterans. Yet their relative impacts on postdeployment functioning are not well understood. The current study used structural equation modeling (SEM) to clarify the extent to which symptoms of internalizing disorders (e.g., depression, anxiety), mTBI symptoms, and cognitive performance are associated with functional impairment in 295 combat-exposed veterans. SEM results showed that internalizing symptoms most significantly predicted functional impairment (r = 0.72). Blast mTBI and cognitive performance were associated with internalizing (r = 0.24 and -0.25, respectively), but functional impairment was only modestly related to cognition (r = -0.17) and unrelated to mTBI. These results indicate that internalizing symptoms are the strongest predictor of functioning in trauma-exposed veterans, exceeding the effects of mTBI and cognitive performance. This evidence supports prioritizing interventions that target internalizing psychopathology to improve functioning in cases of co-occurring PTSD and mTBI.

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).

Mild Cognitive Impairment and driving: Does in-vehicle distraction affect driving performance?

OBJECTIVES

In-vehicle distraction is considered to be an important cause of road accidents. Drivers with Mild Cognitive Impairment (MCI), because of their attenuated cognitive resources, may be vulnerable to the effects of distraction; however, previous relevant research is lacking. The main objective of the current study was to explore the effect of in-vehicle distraction on the driving performance of MCI patients, by assessing their reaction time at unexpected incidents and accident probability.

METHODS

Thirteen patients with MCI (age: 64.5±7.2) and 12 cognitively intact individuals (age: 60.0±7.7), all active drivers were introduced in the study. The driving simulator experiment included three distraction conditions: (a) undistracted driving, (b) conversing with passenger and (c) conversing through a hand-held mobile phone.

RESULTS

The mixed ANOVA models revealed a greater effect of distraction on MCI patients. Specifically, the use of mobile phone induced a more pronounced impact on reaction time and accident probability in the group of patients, as compared to healthy controls. On the other hand, in the driving condition "conversing with passenger" the interaction effects regarding reaction time and accident probability were not significant. Notably, the aforementioned findings concerning the MCI patients in the case of the mobile phone were observed despite the effort of the drivers to apply a compensatory strategy by reducing significantly their speed in this driving condition.

CONCLUSION

Overall, the current findings indicate, for the first time, that a common driving practice, such as the use of mobile phone, may have a detrimental impact on the driving performance of individuals with MCI.

Office-Based Assessment of At-Risk Driving in Older Adults With and Without Cognitive Impairment

BACKGROUND

A multitest approach is optimal for the identification of at-risk driving among older adults. This study examined the predictive validity of a combination of office-based screening tests for on-road driving performance in older adults with and without mild cognitive impairment (MCI)/dementia.

METHODS

Forty-four normal control, 20 participants with MCI, and 20 participants with dementia completed a battery of office-based assessments. On-road driving evaluation classified participants as not at-risk (n = 65) or at-risk drivers (n = 19).

RESULTS

Logistic regression revealed age and 2 tests of visual attention abilities (Useful Field of View [UFOV] Divided Attention and Neuropsychological Assessment Battery [NAB] Driving Scenes) best predicted at-risk drivers ( C statistic = 0.90); no cutoff score had both sensitivity and specificity >80%.

CONCLUSIONS

Future research on larger and more clinically representative neurological samples will improve understanding of the utility of the UFOV Divided Attention and NAB Driving Scenes in detecting at-risk older adult drivers in the clinic.

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.

Neuropsychological Assessment of Driving Capacity

Clinicians are increasingly requested to make determinations regarding patients' driving capacity in the context of neurological injury/conditions and a growing cohort of older drivers. The capability to drive safely involves a number of cognitive, physical, and sensorimotor abilities that may be impacted by injury, illness, or substances that influence alertness. Neuropsychological measures are an important component of a multidisciplinary approach for evaluation of driving capacity. Clinicians should become familiar with measures that have the best predictive validity so they may incorporate a patient's neurocognitive strengths and weaknesses in decisions about driving ability.

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.

Road safety in an aging population: risk factors, assessment, interventions, and future directions

With the number of older drivers projected to increase by up to 70% over the next 20 years, preventing injury resulting from crashes involving older drivers is a significant concern for both policy-makers and clinicians. While the total number of fatal crashes per annum has steadily decreased since 2005 in Australia, the rate of fatalities has demonstrated an upward trend since 2010 in drivers aged 65 years and above (8.5 per 100,000), such that it is now on par with the fatality rate in drivers aged 17-25 years (8.0 per 100,000) (Austroads, 2015). Similar statistics are reported for the United States (NHTSA, 2012), implying there is a need for better identification of those older drivers who are unsafe and implementation of strategies that can enhance mobility while maximizing road safety.

Comparing the driving behaviours of individuals with frontotemporal lobar degeneration and those with Alzheimer's disease

BACKGROUND

Assessing driving aptitude in dementia patients is critically important for both patient and public safety. However, there have been only a few reports on the driving behaviours and accident risk of patients with dementia, especially frontotemporal lobar degeneration (FTLD). Therefore, we compared the characteristics of driving behaviours in patients with FTLD and those with Alzheimer's disease (AD).

METHODS

The subjects were 28 FTLD and 67 AD patients who visited the Department of Psychiatry, Kochi Medical School Hospital. We conducted semi-structured interviews with their families and caregivers about traffic accident history and changes in patient driving behaviours after dementia onset and then compared the findings between the two groups.

RESULTS

Overall changes in driving behaviours were reported in 89% (25/28) and 76% (51/67) of the FTLD and AD patients, respectively (P = 0.17). In the FTLD group, difficulty in judging inter-vehicle distances, ignoring road signs and traffic signals, and distraction were reported in 50% (14/28), 61% (17/28), and 50% (14/28) of patients, respectively, and 75% (21/28) patients had caused a traffic accident after dementia onset. The risk of causing an accident was higher in the FTLD group than in the AD group (odds ratio = 10.4, 95% confidence interval = 3.7-29.1). In addition, the mean duration between dementia onset and a traffic accident was 1.35 years in the FTLD group compared with 3.0 years in the AD group (P < 0.01).

CONCLUSIONS

Patients with FTLD were more likely to show dangerous driving behaviours than those with AD, and the risk of causing a traffic accident may be higher in patients with FTLD from an early disease stage.

Reduced Physical Fitness in Patients With Heart Failure as a Possible Risk Factor for Impaired Driving Performance

OBJECTIVE

Reduced physical fitness secondary to heart failure (HF) may contribute to poor driving; reduced physical fitness is a known correlate of cognitive impairment and has been associated with decreased independence in driving. No study has examined the associations among physical fitness, cognition, and driving performance in people with HF.

METHOD

Eighteen people with HF completed a physical fitness assessment, a cognitive test battery, and a validated driving simulator scenario.

RESULTS

Partial correlations showed that poorer physical fitness was correlated with more collisions and stop signs missed and lower scores on a composite score of attention, executive function, and psychomotor speed. Cognitive dysfunction predicted reduced driving simulation performance.

CONCLUSION

Reduced physical fitness in participants with HF was associated with worse simulated driving, possibly because of cognitive dysfunction. Larger studies using on-road testing are needed to confirm our findings and identify clinical interventions to maximize safe driving.

Tackling Societal Challenges Related to Ageing and Transport Transition: An Introduction to Philosophical Principles of Causation Adapted to the Biopsychosocial Model

In geriatrics, driving cessation is addressed within the biopsychosocial model. This has broadened the scope of practitioners, not only in terms of assessing fitness to drive, but also by helping to maintain social engagements and provide support for transport transition. Causes can be addressed at different levels by adapting medication, improving physical health, modifying behaviour, adapting lifestyle, or bringing changes to the environment. This transdisciplinary approach requires an understanding of how different disciplines are linked to each other. This article reviews the philosophical principles of causality between fields and provides a framework for understanding causality within the biopsychosocial model. Understanding interlevel constraints should help practitioners overcome their differences, and favor transversal approaches to driving cessation.

Mobility and safety issues in drivers with dementia

Although automobiles remain the mobility method of choice for older adults, late-life cognitive impairment and progressive dementia will eventually impair the ability to meet transport needs of many. There is, however, no commonly utilized method of assessing dementia severity in relation to driving, no consensus on the specific types of assessments that should be applied to older drivers with cognitive impairment, and no gold standard for determining driving fitness or approaching loss of mobility and subsequent counseling. Yet, clinicians are often called upon by patients, their families, health professionals, and driver licensing authorities to assess their patients' fitness-to-drive and to make recommendations about driving privileges. We summarize the literature on dementia and driving, discuss evidenced-based assessments of fitness-to-drive, and outline the important ethical and legal concerns. We address the role of physician assessment, referral to neuropsychology, functional screens, dementia severity tools, driving evaluation clinics, and driver licensing authority referrals that may assist clinicians with an evaluation. Finally, we discuss mobility counseling (e.g. exploration of transportation alternatives) since health professionals need to address this important issue for older adults who lose the ability to drive. The application of a comprehensive, interdisciplinary approach to the older driver with cognitive impairment will have the best opportunity to enhance our patients' social connectedness and quality of life, while meeting their psychological and medical needs and maintaining personal and public safety.

Performance of the Maze Navigation Test in a sample of older New Zealanders

OBJECTIVE

It is often difficult to assess the driving performance of people with mild dementia. The Maze Navigation Test (MNT) was developed in the USA and has been shown to predict driving performance. The aim of this study is to evaluate how the MNT is performed against three commonly used bedside cognitive screening tools and compare our findings with the US population.

METHODS

A convenience sample of 42 cognitively intact older people (age ≥65) completed the MNT, Mini-Mental State Examination, the revised Addenbrooke's Cognitive Examination and the Trail Making Tests.

RESULTS

The mean MNT completion time was 307.6 (SD=85.6) and 444.5 (SD=157.3) for the 65-74 years and 75-84 years age group, respectively. Pearson's product-moment correlations were strongest with the Trail Making Test Part B (r=0.602).

CONCLUSIONS

The findings of this study were comparable with the initial US data. The MNT is an easy-to-administer bedside cognitive screening tool. Further validation studies using the MNT and driving performance are warranted.

Consensus statements on driving for persons with dementia

The presence of dementia can have a profound effect on a person's capacity for driving, and will lead to eventual cessation of driving and reliance on alternative transportation options. This paper offers evidence and discussion that affirm eight consensus statements related to drivers with dementia and the impact of dementia on the driving task. These statements offer guidance for occupational therapy practitioners when addressing driving and community mobility, a valued instrumental task of daily living.

Cognitive functioning differentially predicts different dimensions of older drivers' on-road safety

The extent to which deficits in specific cognitive domains contribute to older drivers' safety risk in complex real-world driving tasks is not well understood. We selected 148 drivers older than 70 years of age both with and without neurodegenerative diseases (Alzheimer disease-AD and Parkinson disease-PD) from an existing driving database of older adults. Participant assessments included on-road driving safety and cognitive functioning in visuospatial construction, speed of processing, memory, and executive functioning. The standardized on-road drive test was designed to examine multiple facets of older driver safety including navigation performance (e.g., following a route, identifying landmarks), safety errors while concurrently performing secondary navigation tasks ("on-task" safety errors), and safety errors in the absence of any secondary navigation tasks ("baseline" safety errors). The inter-correlations of these outcome measures were fair to moderate supporting their distinctiveness. Participants with diseases performed worse than the healthy aging group on all driving measures and differences between those with AD and PD were minimal. In multivariate analyses, different domains of cognitive functioning predicted distinct facets of driver safety on road. Memory and set-shifting predicted performance in navigation-related secondary tasks, speed of processing predicted on-task safety errors, and visuospatial construction predicted baseline safety errors. These findings support broad assessments of cognitive functioning to inform decisions regarding older driver safety on the road and suggest navigation performance may be useful in evaluating older driver fitness and restrictions in licensing.

A neuropsychological instrument measuring age-related cerebral decline in older drivers: development, reliability, and validity of MedDrive

When facing age-related cerebral decline, older adults are unequally affected by cognitive impairment without us knowing why. To explore underlying mechanisms and find possible solutions to maintain life-space mobility, there is a need for a standardized behavioral test that relates to behaviors in natural environments. The aim of the project described in this paper was therefore to provide a free, reliable, transparent, computer-based instrument capable of detecting age-related changes on visual processing and cortical functions for the purposes of research into human behavior in computational transportation science. After obtaining content validity, exploring psychometric properties of the developed tasks, we derived (Study 1) the scoring method for measuring cerebral decline on 106 older drivers aged ≥70 years attending a driving refresher course organized by the Swiss Automobile Association to test the instrument's validity against on-road driving performance (106 older drivers). We then validated the derived method on a new sample of 182 drivers (Study 2). We then measured the instrument's reliability having 17 healthy, young volunteers repeat all tests included in the instrument five times (Study 3) and explored the instrument's psychophysical underlying functions on 47 older drivers (Study 4). Finally, we tested the instrument's responsiveness to alcohol and effects on performance on a driving simulator in a randomized, double-blinded, placebo, crossover, dose-response, validation trial including 20 healthy, young volunteers (Study 5). The developed instrument revealed good psychometric properties related to processing speed. It was reliable (ICC = 0.853) and showed reasonable association to driving performance (R (2) = 0.053), and responded to blood alcohol concentrations of 0.5 g/L (p = 0.008). Our results suggest that MedDrive is capable of detecting age-related changes that affect processing speed. These changes nevertheless do not necessarily affect driving behavior.

The use of meta-analysis or research synthesis to combine driving simulation or naturalistic study results on driver distraction

Three important and inter-related topics are addressed in this paper. First, the importance of meta-analysis and research synthesis methods to combine studies on traffic safety, in general, and on driver distraction, in particular, is briefly reviewed. Second, naturalistic, epidemiologic, and driving simulation studies on driver distraction are used to illustrate convergent and divergent results that have accumulated thus far in this domain of research. In particular, mobile phone conversation, passenger presence, and text messaging naturalistic studies use meta-analyses and research syntheses to illustrate important patterns of results that are in need of more in-depth study. Third, a number of driver distraction study limitations such as poorly defined dependent variables, lack of methodological detail, and omission of statistical information prevent the integration of many studies into meta-analyses. In addition, the overall quality of road safety studies suffers from these same limitations and suggestions for improvement are made to guide researchers and reviewers. Practical Applications. The use of research synthesis and meta-analysis provide comprehensive estimates of the impact of distractions on driving performance, which can be used to guide public policy and future research.

Comparison of assessments of fitness to drive for people with dementia

Cognitive tests are used to inform recommendations about the fitness to drive of people with dementia. The Rookwood Driving Battery (RDB) and Dementia Drivers' Screening Assessment (DDSA) are neuropsychological batteries designed to assist in this process. The aim was to assess the concordance between the classifications (pass/fail) of the RDB and DDSA in individuals with dementia, and to compare any discordant classifications against on-road driving ability. Participants were identified by community mental health teams and psychiatrists. Twenty four participants were recruited. The mean age was 74.1 (SD 8.9) years and 18 (75%) were men. Each participant was assessed on the RDB and DDSA in an order determined by random allocation. Those with discrepant results also had an on-road assessment. The agreement between the tests was 54% using a cut-off of > 6 on the RDB, and 75% using the cut-off to > 10 on the RDB. Three participants with discrepant results agreed to be assessed on the road and all were found to be safe to drive. The findings suggested that there was poor concurrent validity between the RDB and DDSA. This raises questions about the choice of assessments in making clinical recommendations about fitness to drive in people with dementia.

A novel computer test to assess driving-relevant cognitive functions--a pilot study

BACKGROUND

The assessment of driving-relevant cognitive functions in older drivers is a difficult challenge as there is no clear-cut dividing line between normal cognition and impaired cognition and not all cognitive functions are equally important for driving.

METHODS

To support decision makers, the Bern Cognitive Screening Test (BCST) for older drivers was designed. It is a computer-assisted test battery assessing visuo-spatial attention, executive functions, eye-hand coordination, distance judgment, and speed regulation. Here we compare the performance in BCST with the performance in paper and pencil cognitive screening tests and the performance in the driving simulator testing of 41 safe drivers (without crash history) and 14 unsafe drivers (with crash history).

RESULTS

Safe drivers performed better than unsafe drivers in BCST (Mann-Whitney U test: U = 125.5; p = 0.001) and in the driving simulator (Student's t-test: t(44) = -2.64, p = 0.006). No clear group differences were found in paper and pencil screening tests (p > 0.05; ns). BCST was best at identifying older unsafe drivers (sensitivity 86%; specificity 61%) and was also better tolerated than the driving simulator test with fewer dropouts.

CONCLUSIONS

BCST is more accurate than paper and pencil screening tests, and better tolerated than driving simulator testing when assessing driving-relevant cognition in older drivers.

Lower hippocampal volume predicts decrements in lane control among drivers with amnestic mild cognitive impairment

OBJECTIVES

There are few methods to discern driving risks in patients with early dementia and mild cognitive impairment (MCI). We aimed to determine whether structural magnetic resonance imaging (MRI) of the hippocampus-a biomarker of probable Alzheimer pathology and a measure of disease severity in those affected--is linked to objective ratings of on-road driving performance in older adults with and without amnestic MCI.

METHODS

In all, 49 consensus-diagnosed participants from an Alzheimer's Disease Research Center (15 diagnosed with amnestic MCI and 34 demographically similar controls) underwent structural MRI and on-road driving assessments.

RESULTS

Mild atrophy of the left hippocampus was associated with less-than-optimal ratings in lane control but not with other discrete driving skills. Decrements in left hippocampal volume conferred higher risk for less-than-optimal lane control ratings in the patients with MCI (B = -1.63, standard error [SE] = .74, Wald = 4.85, P = .028), but not in controls (B = 0.13, SE = .415, Wald = 0.10, P = .752). The odds ratio and 95% confidence interval for below-optimal lane control in the MCI group was 4.41 (1.18-16.36), which was attenuated to 3.46 (0.88-13.60) after accounting for the contribution of left hippocampal volume.

CONCLUSION

These findings suggest that there may be a link between hippocampal atrophy and difficulties with lane control in persons with amnestic MCI. Further study appears warranted to better discern patterns of brain atrophy in MCI and Alzheimer disease and whether these could be early markers of clinically meaningful driving risk.