Road Test and Naturalistic Driving Performance in Healthy and Cognitively Impaired Older Adults: Does Environment Matter?

Objectives

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

Design

Cross‐sectional observational study.

Setting

Academic medical center memory disorders clinic.

Participants

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

Measurements

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

Results

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

Conclusion

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

Prediction of on-road driving performance in patients with early Alzheimer's disease

OBJECTIVES: Physicians and family members frequently are asked to provide information about driving ability in patients with Alzheimer's disease (AD), yet there has been little research on the validity of their assessments of driving performance. DESIGN: Cross-sectional. SETTING: Participants were recruited from the neurology department of a community hospital affiliated with Brown Medical School. PARTICIPANTS: Participants included 75 older adults (17 with mild AD, 33 with very mild AD, and 25 elderly controls). MEASUREMENTS: The participant him/herself, an informant, and an experienced neurologist rated each participant's driving ability on a 3-point rating scale (safe, marginal, unsafe). A professional driving instructor also completed a standardized 108-point on-road driving assessment of each participant and then rated driving ability on the 3-point scale. Ratings were compared with the on-road driving score and with each other. RESULTS: Only the neurologist's rating of the participants' driving abilities was significantly related to on-road driving score. When related to the instructor's safety rating, the neurologist's ratings were the most sensitive and specific. Mini-Mental State Examination score was a borderline covariate for the neurologist's rating. Overall, the instructor was the most stringent rater of participant driving ability, followed by the neurologist, the informant, and the participant. CONCLUSION: An experienced neurologist's assessment of driving competence may be a valid predictor of driving performance of patients with early AD.     

Vision and driving self-restriction in older adults

OBJECTIVES: To assess driving self-restriction (vision related and nonvision related) in relation to vision test performance of older adults. DESIGN: Cross-sectional study. SETTING: Population-based cohort of community-dwelling older adults. PARTICIPANTS: Six hundred twenty-nine current drivers aged 55 and older had driving behavior, health, and physical function assessed and vision function tested in 1993-95. MEASUREMENTS: Self-report of driving restriction as vision or non-vision related and performance on a comprehensive battery of vision tests (visual acuity; contrast sensitivity; effects of illumination level, contrast, and glare on acuity; visual fields with and without attentional load; color vision; temporal sensitivity; and the effect of dim light on walking ability). RESULTS: Demographic, health, and functional characteristics differed significantly between restrictors and nonrestrictors but not between vision- and nonvision-related restrictors. Controlling for potential confounding, only vision-related driving self-restriction was significantly associated with reduced performance on nonstandard measures of acuity. Poor depth perception was significantly associated with restriction for both vision- and nonvision-related reasons. Poor performance on attentional visual field tests, analyzed individually and in combination with standard field tests, was not associated with driving self-restriction. CONCLUSION: Older adults with early changes in spatial vision function and depth perception appear to recognize their limitations and restrict their driving even if they do not acknowledge the visual impairment as the cause for restriction. Poor visual attention, a risk factor for crashes, may not be recognized. Additional studies of driving self-restriction in relation to risk factors for crashes in older adults may help refine this strategy of reducing driving-related injury and death.     

A multidomain approach for predicting older driver safety under in-traffic road conditions

OBJECTIVES: To identify a battery of tests that predicts safe and unsafe performance on an on-road assessment of driving.
DESIGN: Prospective cohort study.
SETTING: University laboratory assessment and an on-road driving test.
PARTICIPANTS: Two hundred seventy community-living adults aged 70 to 88 recruited through the electoral roll.
MEASUREMENTS: Performance on a battery of multidisciplinary tests and on a standardized measure of on-road driving performance.
RESULTS: A combination of three tests from the vision, cognitive, and motor domains, including motion sensitivity, color choice reaction time, postural sway on a compliant foam rubber surface, and a self-reported measure of driving exposure, was able to classify participants into safe and unsafe driver groups with sensitivity of 91% and specificity of 70%.
CONCLUSION: In a sample of licensed older drivers, a short battery of tests and a self-reported measure of driving exposure were able to accurately predict driving safety.     

Awareness of Functional Difficulties in Mild Cognitive Impairment: A Multidomain Assessment Approach

OBJECTIVES: To determine whether patients with mild cognitive impairment (MCI) are fully aware of and provide reliable estimates of their functional status.
DESIGN: Controlled, matched-samples, cross-sectional study.
SETTING: University medical and research centers.
PARTICIPANTS: Fifty-seven persons with amnestic MCI and 68 normal controls.
MEASUREMENTS: The study examined accuracy of self-report in MCI across five functional domains (driving, financial abilities, medication management, grocery shopping, and telephone use) by comparing patients' report of functioning with their performance on laboratory-based measures of function.
RESULTS: The discrepancy between self-report and objective performance was significantly higher in patients with MCI than in their cognitively normal peers only on financial abilities. Patients with MCI overestimated their abilities on this functional domain. Patients with MCI also tended to overestimate their driving abilities, although this was not statistically significant.
CONCLUSION: These findings provide evidence that awareness of functional difficulties is not a unitary construct; rather, it varies across functional domains. They also suggest that self-report of functional abilities in MCI may be, on the whole, as accurate as in cognitively intact older adults. Even so, the self-objective discrepancies noted for both study groups suggest that supplementing self-reported information with objective functional assessment might improve detection of older adults who have begun to experience more functional restriction than is normal for age. In turn, timely identification would permit the targeted implementation of interventions that delay or forestall further deterioration in function.     

Effect of driving training on car crashes and driving skills in older people: A systematic review and meta-analysis

The primary aim of this systematic review was to examine the efficacy of driving interventions with regard to a reduction in motor vehicle crashes and improvements in driving skills among older people. The secondary aim was to identify the optimal type (on-road or off-road) and dosage (period, sessions, and duration) of driving interventions for improving driving skills in older people. We searched MEDLINE, EMBASE, PsycINFO, and Scopus of Systematic Reviews for papers published from their inception to December 1, 2020, as well as the reference lists of the included papers. The selected studies were randomized controlled trials examining the effects of driving interventions among community-dwelling older drivers aged 65 years and over. A meta-analysis of two studies (n = 960) showed that driving interventions significantly reduced the number of motor vehicle crashes per person-years. Ten studies (n = 575) were included in the meta-analysis showing that the interventions significantly improved the driving skill scores. Driving skill scores significantly improved after on-road training, and in interventions of at least 3 h, 3 sessions, and 3 weeks. Driving interventions significantly improve driving skills and reduce motor vehicle crashes among older drivers aged 65 years and over. On-road training is more efficacious than off-road training and driving interventions of at least 3 h taking place in 3 sessions over a period of 3 weeks may be required to improve driving skills in older drivers. Geriatr Gerontol Int 2023; 23: 771–778 .     

Health conditions, health symptoms and driving difficulties in older adults

OBJECTIVES: Previous research has indicated that age-related medical or health conditions can affect driving performance in older adults but little, if any, research has examined the mechanisms through which health conditions affect driving difficulties in older adults. DESIGN: Cross-sectional, correlational study. SETTING: Random sample from the community. We examined the nature of the relations among health conditions, health-related symptoms, physical fitness levels and specific types of self-reported driving difficulties in a random sample of older adults. PARTICIPANTS: Three hundred eighteen adults 60 years of age or older. INTERVENTION: None. MEASUREMENTS: General health, health-related symptoms, driving-related difficulties and physical activity. RESULTS: Our findings support the position that health-related symptoms are more clearly associated with driving difficulties than are health conditions, and mediate the relations between health conditions and driving difficulties. Health-related symptoms involving the spine and lower body appeared to be particularly relevant to difficulties with driving experienced in those body areas (i.e. spine and lower body). CONCLUSION: These findings are encouraging, in that the most frequently reported symptoms are in areas highly amenable to modification and, in that most of our respondents indicated a willingness to engage in exercise if an association between fitness and driving was demonstrated.     

Causes of Therapeutic Errors in Older Adults: Evaluation of National Poison Center Data

OBJECTIVES: To evaluate the reasons for unintentional therapeutic errors in older adults, the types of medications most frequently involved, and the medical outcomes related to these adverse drug events.
DESIGN: Retrospective analysis of American Association of Poison Control Center's National Poison Data System (NPDS).
SETTING: NPDS collects data from all U.S. poison centers. Data from 2002 to 2006 were examined.
PARTICIPANTS: Cases involving adults aged 65 and older with a potentially toxic exposure due to unintentional therapeutic errors.
MEASUREMENTS: Hazard factor analysis was conducted to identify medications that pose risk in this population.
RESULTS: There were 140,786 older adults with reported therapeutic errors, of which 49,320 cases were followed to a known medical outcome. A major effect or death occurred in 596 cases (1.2% of cases with known medical outcome). The most common reasons for therapeutic errors were inadvertently took or given medication twice, wrong medication taken or given, and other incorrect dose. The reasons associated with the highest rate of major effect or death were drug interaction, health professional or iatrogenic error, and more than one product containing same ingredient. Certain medication classes such as analgesics, anticoagulants, anticonvulsants, asthma therapies, psychotherapeutics, and some cardiovascular agents were associated with high hazard factors.
CONCLUSION: Poison center data can be used to evaluate therapeutic errors in older adults to identify reasons associated with frequently reported errors, as well as reasons and medications involved with errors that result in serious outcomes. Knowing the reasons why they occur can aid in developing strategies for decreasing unintentional errors in older adults.     

The effects of age and alcohol intoxication on simulated driving performance, awareness and self-restraint

AIMS: To investigate whether, compared with middle-aged men (aged 30-50), older men (age > or =60) (i) perform more poorly on a driving simulator and (ii) are more sensitive to the effects of ethanol in terms of blood alcohol concentration (BAC) and driving performance, but more aware of their driving difficulties, and therefore exercise better driving judgement. METHODS: 14 Healthy middle-aged men (mean age 36 years) were compared with 14 healthy older men (mean age 69 years) on an interactive driving simulator, while sober and while legally intoxicated (BAC >80 mg/dl). RESULTS: Older age was associated with poorer driving performance on the simulator. While sober, older men exhibited more improper braking, slower driving, greater speed variability, fewer appropriate full stops and more crashes, and spent more time executing left turns (across oncoming traffic); all values < or =0.02. BACs > or =80 mg/dl were associated with impaired driving, with more inappropriate braking, fewer appropriate full stops and more time executing left turns (all values > or =0.02) and trends towards more speed variability, more low speed collisions and more wrong turns (values <0.1). However, similar ethanol consumption did not produce higher peak BAC or more driving impairments in older drivers. While there were no differences between age groups in terms of awareness of intoxication or driving difficulties, older men were unwilling to drive while legally intoxicated because of fear of physical injury, whereas middle-aged men were more likely to avoid driving when intoxicated due to fear of legal ramifications. CONCLUSION: While both age and legal intoxication affected driving performance, older men were no more sensitive to ethanol in terms of peak BACs, driving performance or awareness/judgement than middle-aged men.     

Clinician assessment of the driving competence of patients with dementia

OBJECTIVES: To determine the validity and reliability of clinician ratings of the driving competence of patients with mild dementia. DESIGN: Observational study of a cross-section of drivers with mild dementia based on chart review by clinicians with varying types of expertise and experience. SETTING: Outpatient dementia clinic. PARTICIPANTS: Fifty dementia subjects from a longitudinal study of driving and dementia. MEASUREMENTS: Each clinician reviewed information from the clinic charts and the first study visit. The clinician then rated the drivers as safe, marginal, or unsafe. A professional driving instructor compared these ratings with total driving scores on a standardized road test and categorical ratings of driving competence. Clinicians also completed a visual analog scale assessment of variables that led to their determinations of driving competence. RESULTS: Accuracy of clinician ratings ranged from 62% to 78% for the instructor's global rating of safe versus marginal or unsafe. In general, there was moderate accuracy and interrater reliability. Accuracy could have been improved in the least-accurate raters by greater attention to dementia duration and severity ratings, as well as less reliance on the history and physical examination. The most accurate predictors were clinicians specially trained in dementia assessment, who were not necessarily the most experienced in their years of clinical experience. CONCLUSION: Although a clinician may be able to identify many potentially hazardous drivers, accuracy is insufficient to suggest that a clinician's assessment alone is adequate to determine driving competence in those with mild dementia.     

Driving Patterns of Older Adults: Results from the Second Injury Control and Risk Survey

OBJECTIVES: To describe older adults' driving patterns, including self‐imposed driving restrictions and motor vehicle crashes (MVCs). DESIGN: The Second Injury Control and Risk Survey (ICARIS‐2) was a national, random‐digit‐dial telephone survey conducted by the Centers for Disease Control and Prevention in 2001 to 2003. ICARIS‐2 sampled 113,476 English‐ and Spanish‐speaking households, using weighting variables to generate national estimates. RESULTS: The response rate was 48% (N=9,684). Six percent (n=728) of respondents were aged 75 and older. Of these, 85.6% (n=613) were aged 75 to 84, and 14.4% (n=115) were aged 85 and older; 59.2% were female. Three‐fourths (74.9%, 95% confidence interval (CI)=70.4–79.4%) of adults aged 75 to 84 and 69.9% (95% CI=48.2–71.6%) aged 85 and older were current drivers. Most (81.9%; 95% CI=77.6–86.2%) older drivers limited their driving, usually in bad weather (59.0%), at night (57.0%), on long trips (49.6%), in traffic (49.0%), or at high speeds (33.6%); only 15.4% limited driving for medical reasons. Women were more likely to self‐limit driving (odds ratio (OR)=1.83, 95% CI=0.99–3.39). Few (4.2%, 95% CI=2.4–6.1%) older adults reported MVC involvement in the past year as a driver or passenger. In multivariate analysis, drivers living alone (OR=3.93, 95% CI=1.55–9.95) and men (OR=2.59, 95% CI=1.18–5.67) were more likely to report a recent crash; drivers who self‐limited were less likely (OR=0.55, 95% CI=0.18–1.60). CONCLUSION: Large majorities of older adults, including those aged 85 and older, are current drivers. Although many limit driving in hazardous conditions, fewer do for medical reasons. Men and older adults who live alone are more likely to report a recent MVC; those who self‐limit their driving are less likely to report crash involvement.     

Assessment of older drivers in New Zealand: The current system,research and recommendations

The purpose of this article is to clarify the current New Zealand driving licensing requirements for older adults and to provide practical recommendations for those health professionals who make decisions regarding driving ability in older adults. Health professionals involved in the assessment of older drivers were asked to clarify areas where more efficient use could be made of assessment resources. A review of driving literature was performed to find specific factors associated with increased risk of negative driving outcomes in older adults. Particular attention was paid to the suitability of different types of on‐road assessment for certain patient groups, the effect of specific diseases and medications on driving safety, and the effect of cognitive impairment. A list of seven recommendations were compiled which include a focus on appropriate on‐road driving assessment referral, driver refresher courses, cognitive screening for those presenting for licence renewal and sensitive broaching of the topic of driving cessation.     

Hearing impairment affects older people's ability to drive in the presence of distracters

OBJECTIVES: To investigate the effects of hearing impairment and distractibility on older people's driving ability, assessed under real‐world conditions. DESIGN: Experimental cross‐sectional study. SETTING: University laboratory setting and an on‐road driving test. PARTICIPANTS: One hundred seven community‐living adults aged 62 to 88. Fifty‐five percent had normal hearing, 26% had a mild hearing impairment, and 19% had a moderate or greater impairment. MEASUREMENTS: Hearing was assessed using objective impairment measures (pure‐tone audiometry, speech perception testing) and a self‐report measure (Hearing Handicap Inventory for the Elderly). Driving was assessed on a closed road circuit under three conditions: no distracters, auditory distracters, and visual distracters. RESULTS: There was a significant interaction between hearing impairment and distracters, such that people with moderate to severe hearing impairment had significantly poorer driving performance in the presence of distracters than those with normal or mild hearing impairment. CONCLUSION: Older adults with poor hearing have greater difficulty with driving in the presence of distracters than older adults with good hearing.     

Driving cessation: what older former drivers tell us

OBJECTIVES: To understand why older drivers living in a community setting stop driving. DESIGN: A cross-sectional study within a longitudinal cohort. SETTING: A geographically defined community in southern California. PARTICIPANTS: 1,950 respondents age 55 and older who reported ever being licensed drivers. MEASUREMENTS: A mailed survey instrument of self-reported driving habits linked to prior demographic, health, and medical information. RESULTS: Of the 1,950 eligible respondents, 141 had stopped driving within the previous 5 years. Among those who stopped, mean age was 85.5 years, 65.2% were female, and the majority reported they were in very good (43.4%) or good (34.0%) health. Nearly two-thirds reported driving less than 50 miles per week prior to stopping and 12.1% reported a motor vehicle crash during the previous 5 years. The most common reasons reported for stopping were medical (41.0%) and age-related (19.4%). In bivariate analyses, age and miles driven per week were each associated with cessation (P < or = .001). Medical conditions, crashes in the previous 5 years, and gender did not reach statistical significance at the P < or = .05 level. Logistic regression results found that the number of medical conditions was inversely associated with driving cessation. CONCLUSION: The relationship between medical conditions and driving is complex; while medical conditions were the most common reason given for driving cessation, those who stopped had fewer medical conditions than current drivers. This suggests that a broader measure of general health or functional ability may play a dominant role in decisions to stop driving.     

The older driver. Clinical assessment and injury prevention.

Continued increases in the number of older drivers during the next several decades will increase the importance of medical, ethical, and health policy issues related to driving privileges. Physicians have a critical role in examining patients for driving competence and in screening for impairments that increase the risk of motor vehicle injuries. Both age-related and disease-related factors may affect driving ability in older adults. Research related to the impact of chronic diseases, medications, visual problems, and various neurologic disorders should provide guidance to clinicians in the assessment of driving ability. Performance-based functional assessment, including the use of driving simulators and road tests, may provide information that is useful in the evaluation and rehabilitation of possibly impaired older drivers. Further research related to human, vehicular, and environmental factors and the development of intervention strategies for prevention of crashes and crash-related injuries will reduce the risk of injury and death in older adults.     

Visual attention and driving behaviors among community-living older persons

BACKGROUND: Older drivers have higher rates of crashes per mile driven compared with most other drivers, and these crashes result in greater morbidity and mortality. Various aspects of cognition, particularly visual attention, have been linked with crash risk among older individuals. The current study was designed to specify those cognitive variables associated with specific on-road driving behaviors in a sample of older, nonclinic-referred individuals. METHODS: 35 community-residing active drivers aged 72 years and older (M = 80) underwent a standardized, on-road driving evaluation involving parking lot maneuvers, and urban, suburban, and highway driving. They were also administered tests of visual attention, executive function, visuospatial cognition, and memory. RESULTS: Driving score was significantly correlated with visual attention, visual memory, and executive function. Visual attention was associated with 25 of 36 driving behaviors, including those involving scanning the environment, interaction with traffic or pedestrians, and distance judgments. Executive function and visual memory were associated with fewer maneuvers, most of which were a subset of maneuvers that correlated with visual attention. CONCLUSIONS: Visual attention, a cognitive function involving search, selection, and switching, plays an important role in driving risk among older drivers. In the current study, key driving maneuvers involving interaction with other vehicles/pedestrians, such as yielding right of way and negotiating safe turns or merges, have the greatest association with visual attention. Specification of both the cognitive risk factors and their impact on problematic driving maneuvers may provide guidelines for developing targeted interventions to reduce risk among older adults.     

A Randomized Trial of a Physical Conditioning Program to Enhance the Driving Performance of Older Persons

Background As the number of older drivers increases, concern has been raised about the potential safety implications. Flexibility, coordination, and speed of movement have been associated with older drivers’ on road performance. Objective To determine whether a multicomponent physical conditioning program targeted to axial and extremity flexibility, coordination, and speed of movement could improve driving performance among older drivers. Design Randomized controlled trial with blinded assignment and end point assessment. Participants randomized to intervention underwent graduated exercises; controls received home, environment safety modules. Participants Drivers, 178, age ≥ 70 years with physical, but without substantial visual (acuity 20/40 or better) or cognitive (Mini Mental State Examination score ≥24) impairments were recruited from clinics and community sources. Measurements On-road driving performance assessed by experienced evaluators in dual-brake equipped vehicle in urban, residential, and highway traffic. Performance rated three ways: (1) 36-item scale evaluating driving maneuvers and traffic situations; (2) evaluator’s overall rating; and (3) critical errors committed. Driving performance reassessed at 3 months by evaluator blinded to treatment group. Results Least squares mean change in road test scores at 3 months compared to baseline was 2.43 points higher in intervention than control participants (P = .03). Intervention drivers committed 37% fewer critical errors (P = .08); there were no significant differences in evaluator’s overall ratings (P = .29). No injuries were reported, and complaints of pain were rare. Conclusions This safe, well-tolerated intervention maintained driving performance, while controls declined during the study period. Having interventions that can maintain or enhance driving performance may allow clinician–patient discussions about driving to adopt a more positive tone, rather than focusing on driving limitation or cessation.     

Longitudinal driving performance in early-stage dementia of the Alzheimer type

OBJECTIVES: To longitudinally assess on-road driving performance in healthy older adults and those with early-stage dementia of the Alzheimer type (DAT). DESIGN: A prospective longitudinal study. SETTING: Large urban medical center and surrounding area. PARTICIPANTS: A sample of 58 healthy controls, 21 participants with very mild DAT, and 29 participants with mild DAT participated. DAT was diagnosed using validated clinical diagnostic criteria and staged according to the Clinical Dementia Rating (CDR) Scale. MEASUREMENTS: Healthy controls and individuals with very mild DAT and mild DAT were administered a standardized on-road driving assessment over repeated times of testing. RESULTS: Subjects in the CDR=1 group (mild DAT) had a faster rate of receiving a rating of not safe on the driving test than subjects in the CDR=0 group (healthy controls; log rank test, P=.006), and the survival function of the CDR=0.5 group (very mild DAT) fell between those of the CDR=0 and CDR=1 groups. A Cox proportional hazards model indicated a significant difference in survival functions between the CDR=0 and CDR=1 groups after baseline age was controlled for (P<.001). Cox regression analysis also indicated that baseline age was a significant risk factor for a rating of "not safe" (P=.002). CONCLUSION: This study provides longitudinal evidence for a decline in driving performance over time, primarily in early-stage DAT, and supports the need not only for driving assessments, but also for reevaluation of individuals with very mild and mild DAT.     

Characteristics of frail older adult drivers

OBJECTIVES: To determine the prevalence of driving in older adults with mild to moderate physical frailty and to compare characteristics of current frail older adult drivers with those of former drivers in the sample. DESIGN: Retrospective study of frail older adults enrolled in randomized trials of exercise and hormone replacement therapy. SETTING: Urban, academic medical center. PARTICIPANTS: One hundred eighty-three sedentary community-dwelling men and women aged 75 and older with mild to moderate physical frailty, as defined by two of the following three criteria: modified Physical Performance Test (PPT) score between 18 and 32, peak oxygen uptake (VO2) between 10 and 18 mL/kg per minute, and self-report of difficulty or assistance with one activity of daily living (ADL) or two instrumental ADLs. Participants were classified as current or former drivers. MEASUREMENTS: Demographic characteristics, medical diagnoses, medication use, modified PPT score, and psychometric tests. RESULTS: The majority (85%) of the participants were drivers. Former drivers were more likely to be older, be female, reside in congregate independent living for the elderly, have a higher incidence of arthritis and congestive heart failure, take sedating medications, have lower total ADL scores, have lower VO2 peak scores, and have more impairment on tests of cognition and physical strength, although only age, type of residence, and grip strength were independent predictors of driving cessation in the regression analysis. CONCLUSION: Despite the presence of physical frailty, many older adults choose to continue to drive. Further studies are needed to better understand the driving behaviors of frail older adults and explore opportunities for optimizing driving abilities.