Chronological age and age-related cognitive deficits are associated with an increase in multiple types of driving errors in late life.

Objective: Older driver research has mostly focused on identifying that small proportion of older drivers who are unsafe. Little is known about how normal cognitive changes in aging affect driving in the wider population of adults who drive regularly. We evaluated the association of cognitive function and age with driving errors. Method: A sample of 266 drivers aged 70 to 88 years were assessed on abilities that decline in normal aging (visual attention, processing speed, inhibition, reaction time, task switching) and the UFOV?, which is a validated screening instrument for older drivers. Participants completed an on-road driving test. Generalized linear models were used to estimate the associations of cognitive factors with specific driving errors and number of errors in self-directed and instructor navigated conditions. Results: All error types increased with chronological age. Reaction time was not associated with driving errors in multivariate analyses. A cognitive factor measuring speeded selective attention and switching was uniquely associated with the most errors types. The UFOV? predicted blind-spot errors and errors on dual carriageways. After adjusting for age, education, and gender, the cognitive factors explained 7% of variance in the total number of errors in the instructor-navigated condition and 4% of variance in the self-navigated condition. Conclusion: We conclude that among older drivers, errors increase with age and are associated with speeded selective attention, particularly when that requires attending to the stimuli in the periphery of the visual field, task switching, errors inhibiting responses, and visual discrimination. These abilities should be the target of cognitive training. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Simulated driving performance of adults with ADHD: Comparisons with alcohol intoxication.

Previous research has demonstrated that adults with attention deficit/hyperactivity disorder (ADHD) are more likely to experience driving-related problems, which suggests that they may exhibit poorer driving performance. However, direct experimental evidence of this hypothesis is limited. The current study involved 2 experiments that evaluated driving performance in adults with ADHD in terms of the types of driving decrements typically associated with alcohol intoxication. Experiment 1 compared the simulated driving performance of 15 adults with ADHD to 23 adult control participants, who performed the task both while sober and intoxicated. Results showed that sober adults with ADHD exhibited decrements in driving performance compared to sober controls, and that the profile of impairment for the sober ADHD group did in fact resemble that of intoxicated drivers at the blood alcohol concentration level for legally impaired driving in the United States. Driving impairment of the intoxicated individuals was characterized by greater deviation of lane position, faster and more abrupt steering maneuvers, and increased speed variability. Experiment 2 was a dose-challenge study in which 8 adults with ADHD and 8 controls performed the driving simulation task under 3 doses of alcohol: 0.65g/kg, 0.45g/kg, and 0.0g/kg (placebo). Results showed that driving performance in both groups was impaired in response to alcohol, and that individuals with ADHD exhibited generally poorer driving performance than did controls across all dose conditions. Together the findings provide compelling evidence to suggest that the cognitive and behavioral deficits associated with ADHD might impair driving performance in such a manner as to resemble that of an alcohol intoxicated driver. Moreover, alcohol might impair the performance of drivers with ADHD in an additive fashion that could considerably compromise their driving skill even at blood alcohol concentrations below the legal limit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of Alzheimer disease on driving-related abilities

Ten Alzheimer disease (AD) patients and 12 healthy elderly controls were evaluated on two tests of driving-related abilities: the Driver Performance Test (DPT) and the Driving Advisement System (DAS). Subjects were administered a battery of neuropsychological tests to determine if severity of dementia in AD correlates with driving performance. On the DPT, the AD patients scored in the average range in two of five skill areas (predicting the effects of a hazard, deciding how to avoid it); below average in two areas (searching for a hazard, executing evasive actions); and poorly in one area (identifying hazards). The elderly controls scored at an average level in all five skill areas. On the DAS, AD patients were significantly slower than the elderly controls on simple, two-choice, and conditional reaction time tests and were much slower than drivers in general. The AD patients' performances on two cognitive tests, the Mini-Mental State Examination (MMSE) and the Category Fluency Test, correlated significantly with aspects of performance on the DPT and the DAS. Although these are preliminary results from a pilot investigation, they suggest that AD patients' driving-related abilities are adversely affected by the disease and that driving-related performance tests and neuropsychological tests may be useful in assessing the impact of AD on driving.     

The scope and nature of the drowsy driving problem in New York State

A telephone survey was conducted of a random sample of New York State licensed drivers to determine the prevalence and circumstances of drowsy driving. Based on the survey responses, 54.6% of the drivers had driven while drowsy within the past year; 22.6% had ever fallen asleep at the wheel without having a crash, 2.8% had ever crashed when they fell asleep, and 1.9% had crashed when driving while drowsy. Of the reported crashes due to driving while drowsy or falling asleep at the wheel, 82.5% involved the driver alone in the vehicle, 60.0% occurred between 11:00 p.m. and 7:00 a.m. 47.5% were drive-off-road crashes, and 40.0% occurred on a highway or expressway. Multiple regression analysis suggested that the following driver variables are predictive of an increased frequency of driving drowsy: demographic characteristics (younger drivers, more education, and men); sleep patterns (fewer hours of sleep at night and greater frequency of trouble staying awake during the day); work patterns (greater frequency of driving for job and working rotating shifts); and driving patterns (greater number of miles driven annually and fewer number of hours a person can drive before becoming drowsy).     

Pineal and suprasellar metastasis of lung cancer: case report and review of the literature

The ability of elderly citizens to drive safely has been the subject of ongoing debate. To identify the type of elderly driver who becomes involved in an injury-producing road crash, we profiled all drivers over 39 years of age admitted to our Level I Trauma Center over a 1-year period. Data were prospectively collected and drivers age 40-59 years were compared with those over 60 years. Eighty-four drivers age > or = 60 and 130 drivers age 40-59 were studied. Of the 84 elderly drivers, 67 were deemed at fault. Twenty-four of those crashes were due to driving errors, 12 due to syncopes, and in 20 no crash cause was determined. Fifty-three of the 67 at fault drivers had significant underlying medical problems, compared to 9 of 17 deemed not at fault. Only four were legally intoxicated. Of the 130 drivers in the comparison group, only 19 had significant underlying medical problems; in three syncope was suspected; 18 were legally intoxicated. We conclude from our data that underlying medical disorders occur frequently in elderly drivers and may contribute to their incidence of road crashes.     

Selective induction of apoptosis in mouse and human lung epithelial cell lines by the tert-butyl hydroxylated metabolite of butylated hydroxytoluene: a proposed role in tumor promotion

With increasing age, diseases affecting the cognitive functions are more frequent. These diseases may increase the risk for fatal car crashes. We analyzed the frequency of neuropathological alterations characteristic of Alzheimer's disease (i.e. neuritic and diffuse plaques, and neurofibrillary tangles) in two association areas of the brain, parietal and frontal cerebral cortex, from 98 fatally injured aged drivers. In the age groups of 65-75 and over 75 years of age, 50% and 72% of the drivers, respectively, had neuritic plaques in either parietal and/or frontal cortex. In 14% of all killed drivers the number of neuritic plaques reached the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) age-related histologic score C, which indicates the diagnosis of Alzheimer's disease (AD), and an additional 33% had score B, which suggests the diagnosis of AD. Neuropathological AD changes were most common in the brains of drivers killed in single vehicle crashes, followed by multivehicle crashes at intersections and least common in multivehicle crashes elsewhere, but the differences did not reach statistical significance. In a great majority (80-85%) of cases the killed aged driver was the guilty party of the crash. The results imply, that incipient AD may contribute to fatal crashes of aged drivers, and therefore the forensic autopsy of these victims should include neuropathological examination.     

Attention and driving performance in Alzheimer's disease

The present study examined the relationship between visual attention measures and driving performance in healthy older adults and individuals with very mild and mild dementia of the Alzheimer type (DAT). Subjects were administered an on-road driving assessment and three visual attention tasks (visual search, visual monitoring, and useful field of view). The results indicated that error rate and reaction time during visual search were the best predictors of driving performance. Furthermore, visual search performance was predictive of driving performance above and beyond simple dementia severity and several traditional psychometric tests. The results suggest that general cognitive status may be useful for identifying individuals "at risk" for unsafe driving. However, measures of selective attention may serve to better differentiate safe versus unsafe drivers, especially in the DAT population.     

Safety in work vehicles: A multilevel study linking safety values and individual predictors to work-related driving crashes.

Although work-related driving is associated with high accident rates, limited research has investigated the factors influencing driving crashes in the work setting. This study explored multilevel influences on self-reported crashes in the workplace by surveying a sample of work-related drivers (n = 380), their workgroup supervisors (n = 88), and fleet managers (n = 47). At the driver level of analysis, safety motivation predicted self-reported crashes. In turn, drivers' perceptions of their fleet managers' safety values (but not drivers' perceptions of their supervisors' safety values), their own attitudes, and their own efficacy beliefs predicted motivation to drive safely. Furthermore, the influence of supervisors and fleet managers interacted such that drivers were more motivated to drive safely if they perceived both their supervisor and fleet manager to value safety. This study also explored the cross-level relationships between supervisors' and fleet managers' perceptions of organizational safety values and drivers' perceptions of managerial safety values and found a relationship between fleet managers' perceptions of organizational safety values and drivers' perceptions of fleet managers' safety values. These results illustrate that perceptions of workplace safety values are transmitted across levels of the organization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do older drivers with visual and cognitive impairments drive less?

OBJECTIVE: To determine whether older drivers with poorer cognitive and/or visual function drive fewer miles or avoid driving in situations that pose higher crash risks, such as at nighttime, in rush hour traffic, or when weather conditions are bad. DESIGN: A cross-sectional data analysis conducted as part of a larger prospective study. SUBJECTS: A total of 3238 drivers aged 65 and older applying for renewal of their driver's license at one of eight participating North Carolina driver's license offices. MEASUREMENTS: Subjects were administered a battery of brief tests of cognitive and visual function, which included the Trail Making Test Parts A and B, the Short Blessed Orientation-Memory-Concentration test, and measures of high and low contrast visual acuity, contrast sensitivity, and peripheral vision. Participants were also asked to complete a brief driving survey containing questions about the number of miles they drove and whether they avoided driving under certain conditions, such as after dark or on busy, multi-lane roadways. Driver age and gender were covariates in the analyses. RESULTS: Results of multivariate logistic regression models show a clear pattern of reduced driving exposure--lower annual miles and greater avoidance of high-risk driving situations--associated with lower levels of cognitive and visual function. In general, the prevalence odds of reduced driving exposure were higher for the cognitive function variables than for the visual function variables, and higher for males than for females. Men who scored in the lowest quartile of performance on one of the cognitive tests were six to seven times more likely to report driving fewer than 3000 miles a year than were men scoring in the highest quartile, and women with low scores were one-and-one-half to two times more likely to report driving less than 3000 miles than women with higher scores. CONCLUSIONS: While the findings of this study are reassuring, they do not guarantee that all drivers with cognitive and visual impairments are limiting their driving exposure appropriately, and geriatricians and other health professionals should be encouraged to evaluate their patients' cognitive and visual fitness for driving and provide counsel where indicated.     

Interference between concurrent tasks of driving and telephoning.

224 men were given the task of judging whether to drive through gaps which might be larger or smaller than the car, and a telephoning task of checking the accuracy of short sentences. Interference between the concurrently performed tasks was investigated. Telephoning mainly impaired judgments of "impossible" gaps. The control skills employed in steering through "possible" gaps were not reliably degraded, although speed of driving was reduced. Driving increased errors and prolonged RTs on the sentence-checking task. It is concluded that telephoning has a minimal effect on the more automatized driving skills, but that perception and decision-making may be critically impaired by switching between visual and auditory inputs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of young and adult driver crashes in Alaska using linked traffic crash and hospital data

This report describes young driver crashes in Alaska, compares rates and characteristics of young driver crashes with adult driver crashes, and summarizes the medical and financial outcomes of young driver crashes, for the period 1991 through 1995. Using the Mini Crash Outcome Data Evaluation System (MINICODES), trauma registry hospital discharge data were linked with traffic crash records. The data were analyzed to compare drivers aged 16-20 with drivers aged 21-50 who were involved in a crash resulting in the hospitalization or death of a crash victim. The CrashCost Program was used to estimate costs associated with young driver crashes for the five years. Young drivers were 2.9 times more likely than adult drivers to be involved in crashes that resulted in the hospitalization of a crash victim, and 2.6 times more likely to be involved in a crash involving a fatality. The contributing factors for young driver crashes were listed as human factors 73.4% of the time, compared with 65.6% among adults (P = .001). Costs associated with the young driver crashes were estimated to be over $300 million, which resulted in a cost per young licensed driver that was 3.4 times the cost per adult licensed driver.     

Visual processing impairment and risk of motor vehicle crash among older adults

CONTEXT: Motor vehicle crash risk in older drivers has been associated with visual acuity loss, but only weakly so, suggesting other factors contribute. The useful field of view is a measure that reflects decline in visual sensory function, slowed visual processing speed, and impaired visual attention skills. OBJECTIVE: To identify whether measures of visual processing ability, including the useful field of view test, are associated with crash involvement by older drivers. DESIGN: Prospective cohort study with 3 years of follow-up, 1990-1993. SETTING: Ophthalmology clinic assessment of community-based sample. PATIENTS: A total of 294 drivers aged 55 to 87 years at enrollment. MAIN OUTCOME MEASURE: Motor vehicle crash occurrence. RESULTS: Older drivers with a 40% or greater impairment in the useful field of view were 2.2 times (95% confidence interval, 1.2-4.1) more likely to incur a crash during 3 years of follow-up, after adjusting for age, sex, race, chronic medical conditions, mental status, and days driven per week. This association was primarily mediated by difficulty in dividing attention under brief target durations. CONCLUSION: Reduction in the useful field of view increases crash risk in older drivers. Given the relatively high prevalence of visual processing impairment among the elderly, visual dysfunction and eye disease deserve further examination as causes of motor vehicle crashes and injury.     

Semantic inhibition impairment in mild cognitive impairment: A distinctive feature of upcoming cognitive decline?

This study aimed to measure semantic inhibitory capacities in persons with a diagnosis of Alzheimer’s disease (AD) or mild cognitive impairment (MCI), in healthy older and younger adults. This was done by relying on a computerized adaptation of the Hayling task, designed to diminish the likelihood of using alternative noninhibitory strategies. Participants with both AD and MCI showed impaired performance on the inhibition condition. Participants with AD showed both poorer score and an increased number of errors, whereas persons with MCI obtained lower score. There was also an effect of normal aging in the inhibition condition when considering reaction time only. In participants with MCI and AD, there was a significant correlation between lexico-semantic capacities and performance on the automatic condition. Follow-up analysis revealed that participants with MCI who experienced a subsequent significant cognitive decline had impaired performance in the inhibition condition at the time of the experiment, while participants with MCI who remained stable did not. Overall, results indicate that semantic inhibition of a prepotent response is impaired in participants with MCI and may have predictive value regarding future decline, supporting its prognostic role in the early identification of dementia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-regulation of driving in the context of impaired visual attention: Are there gender differences?

Purpose: To investigate whether older men and women differ in self-regulation of driving in the context of objective visual-attention impairments. Method: Participants were 1,543 drivers aged 75 years or older who participated in a state-wide study. They completed an objective measure of visual attention and self-report measures of driving habits and functional status. Crash records were obtained from the state department of public safety. Results: Overall, women reported greater avoidance of difficult driving situations than did men, and drivers with impaired visual attention reported greater driving avoidance than did nonimpaired drivers. However, men were at least as likely as women to modify their driving in the context of impaired visual attention. Conclusion: Gender disparity in self-restriction of driving may not be due to gender differences in risk taking. It is necessary to consider factors associated with restricted driving among older adults because of their susceptibility to mobility compromise. Interventions for improving visual attention and self-regulation of driving may be effective in extending the years of autonomous driving without jeopardizing the safety of the community. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An examination of driving records in a dementia clinic

The driving records of 249 persons referred to an outpatient dementia clinic were examined retrospectively to assess the specificity of the association between diagnosed dementia and increased traffic accidents. The clinic patients were divided into two groups: those who met criteria for dementia and those who did not. For each group, control subjects matched on age, gender, and location of residence were randomly selected from the records of all drivers in the province. The dementia sample had approximately 2.5 times the traffic crash rate of their matched control sample. The not-demented sample had approximately 2.2 times the traffic crash rate of their matched control sample. These individuals exhibited a variety of psychiatric, neurological, and medical conditions which could have affected their driving, and multiple medical problems were often present. Further clarification of the characteristics of "high risk" drivers is required if effective strategies for maximizing independence while minimizing the risk of traffic crashes are to be realized.     

Brain infarction and the clinical expression of Alzheimer disease. The Nun Study

OBJECTIVE: To determine the relationship of brain infarction to the clinical expression of Alzheimer disease (AD). DESIGN: Cognitive function and the prevalence of dementia were determined for participants in the Nun Study who later died. At autopsy, lacunar and larger brain infarcts were identified, and senile plaques and neurofibrillary tangles in the neocortex were quantitated. Participants with abundant senile plaques and some neurofibrillary tangles in the neocortex were classified as having met the neuropathologic criteria for AD. SETTING: Convents in the Midwestern, Eastern, and Southern United States. PARTICIPANTS: A total of 102 college-educated women aged 76 to 100 years. MAIN OUTCOME MEASURES: Cognitive function assessed by standard tests and dementia and AD assessed by clinical and neuropathologic criteria. RESULTS: Among 61 participants who met the neuropathologic criteria for AD, those with brain infarcts had poorer cognitive function and a higher prevalence of dementia than those without infarcts. Participants with lacunar infarcts in the basal ganglia, thalamus, or deep white matter had an especially high prevalence of dementia, compared with those without infarcts (the odds ratio [OR] for dementia was 20.7, 95% confidence interval [95% CI], 1.5-288.0). Fewer neuropathologic lesions of AD appeared to result in dementia in those with lacunar infarcts in the basal ganglia, thalamus, or deep white matter than in those without infarcts. In contrast, among 41 participants who did not meet the neuropathologic criteria for AD, brain infarcts were only weakly associated with poor cognitive function and dementia. Among all 102 participants, atherosclerosis of the circle of Willis was strongly associated with lacunar and large brain infarcts. CONCLUSION: These findings suggest that cerebrovascular disease may play an important role in determining the presence and severity of the clinical symptoms of AD.     

Aging, dementia and automobile driving

According to Norwegian law, drivers 70 years and older must carry a health certificate. This is issued by a general practitioner. If the patient is not supposed to drive because of a medical condition, the doctor should report this to the County Health Officer. This can be problematic, not only because assessing whether a patient fulfills the criteria for driving is difficult, but also because the doctor has obligations to both the public and his patient. These problems are discussed, based on assessment of available literature and on personal experience. Dementia is common in old age and affects approximately 15% of persons aged 75 and older. Patients with moderate and severe dementia should certainly not drive. However, some patients with mild dementia can nevertheless be safe drivers. The problem, however, is to identify the safe drivers among patients with mild dementia. The current regulations on dementia and driving are presented briefly.     

Presidential address. What does the Millennium have in store for the American Society of Parasitologists?

BACKGROUND: Previous studies have reported low conviction rates for drunk drivers injured in motor vehicle crashes and transported to the hospital. The purpose of this study was to evaluate this rate during a recent period and to investigate the variables that predict alcohol-related convictions for injured drunk drivers admitted to our hospital. METHODS: A retrospective review of medical records from January 1991 through May 1997 identified 71 patients who were legally intoxicated drivers injured in motor vehicle crashes. Court records, police reports, and driving records were also obtained. RESULTS: Overall, 51% of the drunk drivers were convicted of alcohol-related offenses and 32% escaped without any conviction. Blood alcohol level and a police officer's estimation of whether the driver had been drinking were significant predictors of an alcohol-related conviction. Age, Injury Severity Score, a police officer's estimation of injury, and the number of people or cars involved in the crash were not significantly associated with legal outcome. CONCLUSION: Although this study shows an important increase in alcohol-related conviction rates, responsibility for further progress will depend on the medical community, law enforcement agencies, and the judicial system working together.     

Executive dysfunction and Alzheimer's disease: Performance on a test of planning ability, the Porteus Maze Test.

Planning ability, as measured by the Porteus Maze Test, was evaluated in 85 Alzheimer's disease (AD) patients and 65 controls. AD patients performed worse on Test Age and 2 of 5 qualitative error scores. Principal components analysis revealed 3 Porteus components: Test Age and First Third Errors; Cut Corner and Cross Line Errors; and Last Third Errors. Among AD patients, factor analysis of Porteus measures and other cognitive tests revealed 4 factors. A nonverbal factor included Test Age and 3 nonverbal measures. A verbal factor included no Porteus measure. The remaining factors resembled the last 2 components from the analysis of Porteus scores alone. Test Age and 4 other cognitive measures correlated with ratings on an activities of daily living scale. Porteus Maze performance was impaired in a substantial number of patients with dementia and may be a useful measure of executive function in this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of age, system experience, and navigation technique on driving with an advanced traveler information system

This paper explores the effects of age, system experience, and navigation technique on driving, navigation performance, and safety for drivers who used TravTek, an Advanced Traveler Information System. The first two studies investigated various route guidance configurations on the road in a specially equipped instrumented vehicle with an experimenter present. The third was a naturalistic quasi-experimental field study that collected data unobtrusively from more than 1200 TravTek rental car drivers with no in-vehicle experimenter. The results suggest that with increased experience, drivers become familiar with the system and develop strategies for substantially more efficient and safer use. The results also showed that drivers over age 65 had difficulty driving and navigating concurrently. They compensated by driving slowly and more cautiously. Despite this increased caution, older drivers made more safety-related errors than did younger drivers. The results also showed that older drivers benefited substantially from a well-designed ATIS driver interface.