Crash Risk For Older Drivers Research Articles

Different deployments of attentional breadth selectively predict UFOV task performance in older adults

The Useful Field of View task (UFOV) is a strong and reliable predictor of crash risk in older drivers. However, while the functional domain of attention is clearly implicated in UFOV performance, the potential role of one specific attentional process remains unclear: attentional breadth (the spatial extent of the attended region around the point of visual fixation). The goal of the present study was to systematically test the role of two distinct aspects of attentional breadth, maintaining a specific breadth of attention and resizing the attended region, in UFOV performance. To this end, 135 older adults completed the UFOV and modified Navon tasks to measure their efficiency in maintaining, contracting, and expanding the breadth of attention. We then examined individual-difference associations between these aspects of attentional breadth deployment and UFOV performance. We found that performance on UFOV Subtask 2 was associated with efficient contraction of attentional breadth (i.e., resizing the attended region to a smaller area), while Subtask 3 performance was associated with the efficiency of expanding attentional breadth (i.e., resizing the attended region to a larger area). The selectivity of these relationships appears to implicate these specific deployments of attentional breadth in how people complete the task, as it suggests that these relationships are not simply attributable to shared variance in a broader domain of cognitive functioning. The implications of these results for our understanding of UFOV, as well as future research directions that test the relative contributions of different cognitive processes in predicting task performance, are discussed.

Does a cautious driving style reduce the crash risk of older drivers? An analysis using a novel driving style recognition method

Older drivers who are aware of their declining functions tend to adopt a cautious driving style to compensate for their declining driving abilities. However, whether cautious older drivers are associated with a reduced crash risk has not been well studied. In this study, we examined the association between older drivers’ cautious driving style and crash risk using a novel driving style recognition method. We proposed a driving style recognition method that does not require predefined thresholds and applied it to the driving data of 71 drivers comprising 59 drivers aged 65 years or older (mean age 72.4; 67.8 % male) and 12 drivers aged 51–64 years (mean age 58.3; 66.7 % male). Drivers were classified into cautious and relatively aggressive groups based on the classification results of their speed, acceleration, and braking styles. The results showed that cautious drivers were characterized by older age, poorer Trail Making Test Part B performance, less frequent night driving, and lower driving exposure, indicating that older drivers may adopt multiple compensatory strategies. Although the crash involvement rate of cautious older drivers was approximately half that of relatively aggressive drivers, the difference was not statistically significant. Furthermore, this difference was expected to decrease when driving exposure was considered. Older drivers who adopted a cautious driving style but were involved in traffic crashes had poorer visual acuity and contrast sensitivity. The results of this study indicate that a cautious driving style alone may not be sufficient to compensate for older drivers’ declining functions, particularly the loss of two visual functions observed in the present study.

Using SHRP2 NDS data to examine infrastructure and other factors contributing to older driver crashes during left turns at signalized intersections

Drivers age 65 and over have higher rates of crashes and crash-related fatalities than other adult drivers and are especially over-represented in crashes during left turns at intersections. This research investigated the use of SHRP2 Naturalistic Driving Study (NDS) data to assess infrastructure and other factors contributing to left turn crashes at signalized intersections, and how to improve older driver safety during such turns. NDS data for trips involving signalized intersections and crash or near-crash events were obtained for two driver age groups: drivers age 65 and over (older drivers) and a sample of drivers age 30−49, along with NDS pre-screening and questionnaire data. Video scoring of all trips was performed to collect additional information on intersection and trip conditions. To identify the most influential factors of crash risk during left turns at signalized intersections, machine learning and regression models were used. The results found that in the obtained NDS dataset, there was a relatively small volume of crashes during left turns at signalized intersections. Further, model results found the statistically significant variables of crash risk for older drivers were associated more with health and cognitive factors rather than the infrastructure or design of the intersections. The results suggest that a study using only SHRP2 NDS data will not lead to definitive findings or recommendations for infrastructure changes to increase safety for older drivers at signalized intersections and during left turns. Moreover, the findings of this study indicates the need to consider other data sources and data collection methods to address this critical literature gap in older driver safety.

Motion perception as a risk factor for motor vehicle collision involvement in drivers ≥ 70 years

PurposeTo evaluate the relationship between visual function and a five-year history of motor vehicle collision rates in older adults. Motion perception impairment was explored as a risk factor for motor vehicle collisions for the first time in this study. Materials and methodsParticipants were licensed drivers ≥70 years old enrolled in the Alabama VIP Older Driver Study who underwent functional assessments for motion perception, distance visual acuity, contrast sensitivity, visual field sensitivity, and visual processing speed. Participants were recruited based on their being patients in an ophthalmology clinic in the year prior to enrollment or had participated in an earlier driving study. Crash reports were obtained from the Alabama Law Enforcement Agency for the 5 years prior to enrollment and mileage estimated using the Driving Habits Questionnaire. Crude and age-adjusted rate ratios (RRs) and 95 % confidence intervals (95 % CIs) were calculated using Poisson regression. Results159 participants enrolled with a mean age of 79 years. The age-adjusted crash rate was higher among those with worse motion perception (RR: 2.7, 95 % CI: 1.4−5.2), severe slowing in visual processing speed (RR: 3.6, 95 % CI: 1.5−8.5), and impaired peripheral visual field sensitivity (RR: 2.4, 95 % CI: 1.3−4.4). ConclusionsAmong a sample of older drivers, crash rates were higher for those with impaired motion perception, severely slowed visual processing speed, and impaired peripheral visual field sensitivity. The association between motion perception and crash risk in older drivers has not been previously reported. Prospective analysis of the Alabama VIP Older Driver Study will examine these risk factors for future collision involvement based on naturalistic driving data.

Driver licensing, motor-vehicle crashes, and moving violations among older adults

IntroductionDriving is important for well-being among older adults, but age-related conditions are associated with driving reduction or cessation and increased crash risk for older drivers. Our objectives were to describe population-based rates of older drivers’ licensing and per-driver rates of crashes and moving violations.Methods: We examined individual-level statewide driver licensing, crash, and traffic citation data among all New Jersey drivers aged ≥ 65 and a 35- to 54-year-old comparison group during 2010–2014. Rate ratios (RR) of crashes and moving violations were estimated using Poisson regression.Results: Overall, 86% of males and 71% of females aged ≥ 65 held a valid driver’s license. Older drivers had 27% lower per-driver crash rates than middle-aged drivers (RR: 0.73, 95% CI: 0.73, 0.74)—with appreciable differences by sex—but 40% higher fatal crash rates (RR: 1.40 [1.24, 1.58]). Moving violation rates among older drivers were 72% lower than middle-aged drivers (RR: 0.28 [0.28, 0.28]).Conclusion: The majority of older adults are licensed, with substantial variation by age and sex. Older drivers have higher rates of fatal crashes but lower rates of moving violations compared with middle-aged drivers.Practical applications: Future research is needed to understand the extent to which older adults drive and to identify opportunities to further reduce risk of crashes and resultant injuries among older adults.

The effects of age and cognitive load on peripheral-detection performance.

Age-related declines in both peripheral vision and cognitive resources could contribute to the increased crash risk of older drivers. However, it is unclear whether increases in age and cognitive load result in equal detriments to detection rates across all peripheral target eccentricities (general interference effect) or whether these detriments become greater with increasing eccentricity (tunnel effect). In the current study we investigated the effects of age and cognitive load on the detection of peripheral motorcycle targets (at 5°–30° eccentricity) in static images of intersections. We used a dual-task paradigm in which cognitive load was manipulated without changing the complexity of the central (foveal) visual stimulus. Each image was displayed briefly (250 ms) to prevent eye movements. When no cognitive load was present, age resulted in a tunnel effect; however, when cognitive load was high, age resulted in a general interference effect. These findings suggest that tunnel and general interference effects can co-occur and that the predominant effect varies with the level of demand placed on participants' resources. High cognitive load had a general interference effect in both age groups, but the effect attenuated at large target eccentricities (opposite of a tunnel effect). Low cognitive load had a general interference effect in the older but not the younger group, impairing detection of motorcycle targets even at 5° eccentricity, which could present an imminent collision risk in real driving.

Risk-Exposure Density and Mileage Bias in Crash Risk for Older Drivers.

Crash rates per mile indicate a high risk of vehicle crash in older drivers. A reliance on mileage alone may underestimate the risk exposure of older drivers because they tend to avoid highways and travel more on nonfreeways (e.g., urban roads), which present greater hazards. We introduce risk-exposure density as an index of exposure that incorporates mileage, frequency of travel, and travel duration. Population-wide driver fatalities in the United States during 2002–2012 were assessed according to driver age range (in years: 16–20, 21–29, 30–39, 40–49, 50–59, 60–69, ≥70) and sex. Mileage, frequency, and duration of travel per person were used to assess risk exposure. Mileage-based fatal crash risk increased greatly among male (relative risk (RR) = 1.73; 95% CI: 1.62, 1.83) and female (RR = 2.08; 95% CI: 1.97, 2.19) drivers from ages 60–69 years to ages ≥70 years. Adjusting for their density of risk exposure, fatal crash risk increased only slightly from ages 60–69 years to ages ≥70 years among male (RR = 1.09; 95% CI: 1.03, 1.15) and female (RR = 1.22; 95% CI: 1.16, 1.29) drivers. While ubiquitous in epidemiologic research, mileage-based assessments can produce misleading accounts of driver risk. Risk-exposure density incorporates multiple components of travel and reduces bias caused by any single indicator of risk exposure.

The impact of restricted driver’s licenses on crash risk for older drivers: A systematic review

BackgroundAs the Canadian population ages, there is an urgent need to identify evidence-informed strategies that have the potential to enhance older adults’ safety and independent mobility. Previous research has demonstrated the positive impact of continued independent mobility on older adults’ quality of life, through improvements in health, and community engagement. Restricted driver licensing policies have been mandated in several countries, with the goal of facilitating traffic safety and independent mobility for older drivers. Studies testing the effectiveness of these policies have produced mixed findings; a systematic examination of the impact of restricted driver licensing policies on reducing morbidity and mortality among senior drivers is warranted. AimsThe objectives of this study were to examine if restricted driver licenses are more effective than unrestricted driver licenses in (1) reducing crashes; (2) reducing traffic violations; and (3) facilitating continued independent mobility for older drivers. MethodsA systematic review was completed. A comprehensive electronic database search was conducted to identify all literature related to restricted driver license policies. A total of 3331 abstracts and 39 full text articles were reviewed. Seven papers met the inclusion criteria and were evaluated for quality and risk of bias assessment using the Newcastle-Ottawa Scale (NOS). All seven studies reported motor vehicle collisions as the primary outcome, which included more than 2.1 million participants with or without a driving restriction. The search resulted in a heterogeneous set of included studies, meaning that meta-analysis was not appropriate. A narrative interpretation and discussion of the seven individual studies is presented. ResultsResults demonstrated that restricted driver licensing may be effective at reducing crash risk for older drivers who have few health conditions, and those requiring few driving restrictions. It was noted that medically-restricted drivers incur fewer traffic violations than non-restricted drivers, or drivers with non-medical restrictions. Overall, evidence on both crash risk and traffic violations yielded mixed, yet promising results.Only one included study assessed the impact of restricted licenses on older adults’ independent mobility, with results indicating a positive impact. A major limitation of this body of research is a failure to consider if, and how, restricted licenses facilitate older adults’ independent mobility. DiscussionRestricted driver licensing has the potential to improve traffic safety among the general population and positively impact independent mobility of older Canadians. Efforts should be focused on providing education to health care professionals and motor vehicle licensing authorities on this topic, so that they may advise their clients appropriately, and avoid making premature driving cessation recommendations. Moving forward, more evidence is needed on the direct impact of restricted licensing on older adults’ independent mobility and, more generally, quality of life. ConclusionSupporting older drivers to safely remain independent and engaged in the community has positive impacts on all strata of society. Restricted licensing is one approach that has the potential to promote road safety for all and contribute to improved quality of life for older adults.

Impact of gender on first eye cataract surgery and motor vehicle crash risk for older drivers

No study to date has examined gender differences in crash risk after cataract surgery. Therefore, this study aimed to determine gender-related differences in the effectiveness of first eye cataract surgery in reducing crash risk for older drivers. This retrospective before and after study used whole population linked data to compare the frequency of police reported crashes 1 year before and 1 year after first eye cataract surgery for the years 1997-2006. All patients aged 60-85 years who had first eye cataract surgery between 1997 and 2006 in Western Australia and were involved in a motor vehicle crash 12 months before and/ or after surgery. Two separate generalized estimating equation Poisson models were undertaken for males and females to compare crash frequency before and after surgery. Police-reported crashes before and after cataract surgery. A large proportion of the cohort involved in a crash either 1 year before or 1 year after first eye cataract surgery were male (n = 1091, 63.6%) compared with female (n = 624, 36.3%). Results from the generalized estimating equation Poisson models showed a significant reduction of 15.3% (P = 0.040) in all police reported crash frequency for males 1 year after cataract surgery. However, there was no significant change in crash frequency after surgery for females. The results of this study suggest that clinicians may need to take gender into account when advising patients on driving safety before and after cataract surgery.

Psychotropic Medications and Crash Risk in Older Drivers

. An extensive review of Australian and international literature was undertaken, examining the association between psychotropic medications and crash risk involving older drivers. . The review summarizes the findings in experimental and epidemiological studies related to (a) prevalence of psychotropic medication use among older drivers; (b) side effects of driving under the influence of psychotropic medications; and (c) association between psychotropic medications and crash risk for older drivers. . Current evidence indicates that several types of psychotropic medications have the potential to impair driving ability and increase the risk of crash involvement. A major limitation is that few studies have specifically examined the effects on older drivers, despite the fact that the majority of the population using psychotropic medications are older. Discussion. More knowledge about the safety of therapeutic use of psychotropic medications is needed. Large-scale, whole-population, epidemiological studies, such as data linkage studies, may be the optimal study design.

Declines in fatal crashes of older drivers: Changes in crash risk and survivability

ObjectivesPrevious research has found that older driver fatal crash involvement rates per licensed driver declined substantially in the United States during 1997–2006 and declined much faster than the rate for middle-age drivers. The current study examined whether the larger-than-expected decline for older drivers extended to nonfatal crashes and whether the decline in fatal crash risk reflects lower likelihood of crashing or an improvement in survivability of the crashes that occur. MethodsTrends in the rates of passenger vehicle crash involvements per 100,000 licensed drivers for drivers 70 and older (older drivers) were compared with trends for drivers ages 35–54 (middle-age drivers). Fatal crash information was obtained from the Fatality Analysis Reporting System for years 1997–2008, and nonfatal crash information was obtained from 13 states with good reporting information for years 1997–2005. Analysis of covariance models compared trends in annual crash rates for older drivers relative to rates for middle-age drivers. Differences in crash survivability were measured in terms of the odds of fatality given a crash each year, and the historical trends for older versus middle-age drivers were compared. ResultsFatal crash involvement rates declined for older and middle-age drivers during 1997–2008 (1997–2005 for the 13 state subsample), but the decline for drivers 70 and older far exceeded the decline for drivers ages 35–54 (37 versus 23 percent, nationally; 22 versus 1 percent, 13 states). Nonfatal injury crash involvement rates showed similarly larger-than-expected declines for older drivers in the 13 state subsample, but the differences were smaller and not statistically significant (27 percent reduction for older drivers versus 16 percent for middle-age drivers). Property-damage-only crash involvement rates declined for older drivers (10 percent) but increased for middle-age drivers (1 percent). In 1997, older drivers were 3.5 times more likely than middle-age drivers to die in police-reported crashes (6.2 versus 1.8 deaths per 1000 crashes), but this difference was reduced during the 9-year study period to 2.9 times, as the rate of older drivers dying in a crash declined (5.5 deaths per 1000 crashes in 2005) and the death risk remained relatively stable for middle-age drivers. ConclusionsContrary to expectations based on increased licensure and travel by older drivers, their fatal crash risk has declined during the past decade and has declined at a faster rate than for middle-age drivers. The decreased risk for older drivers appears to extend not only to nonfatal injury crashes but also to property-damage-only crashes, at least as reported to police in the 13 states included in the nonfatal injury analysis. Although insurance collision data suggest that overall crash risk of older drivers may not be changing relative to middle-age drivers, the current analysis indicates that the reduced fatality risk of older drivers reflects both less likelihood of being involved in a police-reported crash and greater likelihood that they will survive when they do crash.

Intersection Crashes among Drivers in their 60s, 70s and 80s

Analyses of National Highway Traffic Safety Administration's Fatality Analysis Reporting System (FARS) and National Automotive Sampling System (NASS)/General Estimates System (GES) data from 2002–2006 revealed specific performance errors and combinations of driver, vehicle, and roadway/environmental characteristics associated with older drivers' crashes at intersections. For subsets of the two-vehicle crash data within each national database, crash involvement ratios based on comparisons of at-fault to not-at-fault drivers within groups of drivers aged <20 to 80+, segregated in 10-year cohorts, provide exposure-adjusted estimates of the magnitude of particular risk factors. While FARS and GES data show elevated crash risk for older drivers, the effect was more pronounced in the FARS data. This exaggeration likely reflects increased frailty with increasing age; young and middle-aged drivers may have survived crashes that were fatal to the oldest drivers. While the data are consistent with the literature in that more complex driving tasks pose the most risk for older drivers, these data also provide information about the scale of the increased risk.

The Effect of Simulated Cataracts on Drivers’ Hazard Perception Ability

We investigated the extent to which simulated cataracts slow a driver's ability to anticipate potential traffic hazards, a skill that has been found to correlate with crash risk. In previous studies, we found a significant correlation between contrast sensitivity and hazard perception in a sample of older drivers. The present study allowed us to determine the causal direction of this relationship. This is important as it provides a better understanding of the mechanisms underlying the higher crash risk of drivers with cataracts. One hundred eighty-six drivers with normal vision completed a validated video-based hazard perception driving test, designed to measure hazard anticipation response times in dynamic scenes. They also completed a change detection task based on traffic hazards, which was designed to measure object detection times in static scenes. Participants undertook the tasks wearing either mild or moderate cataract simulation goggles, or wearing goggle frames without lenses. Participants wearing moderate simulated cataract goggles were slower than the control group in both the hazard perception test, t(98.50) = -3.71, p < 0.001, and the hazard change detection task, t(124) = -13.86, p < 0.001. Participants with the mild simulated cataract goggles were slower than the control group in the hazard change detection task, t(114) = -4.04, p < 0.001, but not the hazard perception test, t(114) = -1.33, p = 0.19. Moderate levels of simulated cataract slowed drivers' ability to detect and anticipate traffic hazards enough to warrant road safety concerns, despite the fact that the vision of participants wearing the cataract goggles still complied with the minimum legal standard required for driving.

The Role of Reduced Fitness to Drive Due to Medical Impairments in Explaining Crashes Involving Older Drivers

Background. Medical conditions and associated impairments are known to be more prevalent with aging and can potentially impact the function and crash risk of older drivers. Objectives. To evaluate the impact of specific medical conditions and associated impairments on older driver crash risk. Methods. A search identified reports and peer-reviewed publications evaluating the risk for medical conditions and associated crash risk. Medical conditions associated with older persons were reviewed to determine the associated relative risk of crash. Results. The review identified three recent comprehensive reviews of medical conditions or chronic illnesses and crash risk: Dobbs (2005); Vaa (2003); Charlton et al. (2004). Comparison of the reviews reveals a relatively high agreement where medical conditions considered to be at slightly to moderately increased relative risk of crash include alcohol abuse and dependence, cardiovascular disease, cerebrovascular disease/TBI, depression, dementia, diabetes mellitus, epilepsy, use of certain medications, musculoskeletal disorders, schizophrenia, obstructive sleep apnea, and vision disorders. However, determining fitness to drive at the individual level based on diagnosis has significant limitations related to factors such as multiple medical conditions as well as varying severity of disease and associated functional impairments. Medical conditions that may affect driving can serve as “red flags” to assist health care professionals and driving administrators to identify drivers who may need further evaluation. Conclusions. Medical conditions overall, do impact the fitness to drive of older drivers; however, the crash risk tends to be only slightly to moderately increased. The conditions can serve as potential warnings for reduced fitness to drive, but many persons with these medical conditions would still be considered safe to continue driving.

Crash risk of older drivers after attending a mature driver education program

Purpose The primary aim of this study was to determine if the crash rate of aging drivers can be mitigated by post-license driver education. Design and methods This study of 884 older drivers who attended the 55 Alive/Mature Driving program was conducted in three phases. Phase 1, which examined self-selection bias of seniors attending the driver education program, and Phase 2, which examined changes in crash rate after attending the program, were carried out through analysis of driving records before and after attending the course. In Phase 3, the use of selection, optimization, and compensation strategies by older male drivers who attended 55 Alive/Mature Driving was addressed through focus group interviews. Results Findings showed a self-selection bias among older drivers who attended 55 Alive/Mature Driving. Results also showed attendance at the program was associated with an increased number of crashes for men aged 75 years and older, but no effect on subsequent crashes of younger men and women of all ages. Focus group sessions suggested older men who attended the program used fewer strategies to cope with their declining skills. Implications Recognizing and understanding characteristics and behaviors of older drivers who attend remedial driver education is essential to the design and delivery of successful driver safety programs.

Traffic-Entry Behavior and Crash Risk for Older Drivers with Impairment of Selective Attention

Current research suggests that older drivers with declines in selective attention would make more unsafe traffic-entry judgments than would older drivers with normal attention. This hypothesis was tested using an instrumented vehicle and a LIDAR speed and range detector. Participants were 20 older drivers: 10 (M=72.0 yr.) had impairments of selective attention, measured with the Visual Attention Analyzer, Model 3000, and 10 were nonimpaired (M=71.2 yr.). Drivers pressed a button to indicate the last possible moment they could safely cross a road in front of an oncoming vehicle. The speed and distance of the oncoming vehicles were measured and time-to-contact was calculated. Each driver's time-to-cross the roadway was independently measured. Attention-impaired drivers showed shorter time-to-contact values (5.60 sec. versus 6.86 sec.), took longer to cross the roadway (5.41 sec. versus 4.84 sec.), and had shorter safety cushions (the difference between time-to-contact and time-to-cross the roadway). Monte Carlo simulation showed that these performance differences increased the crash risk of the impaired group by up to 17.9 times that of the nonimpaired group.

Effectiveness of Mandatory License Testing for Older Drivers in Reducing Crash Risk Among Urban Older Australian Drivers

Most licensing jurisdictions in Australia maintain mandatory assessment programs targeting older drivers, whereby a driver reaching a specified age is required to prove his or her fitness to drive through medical assessment and/or on-road testing. Previous studies both in Australia and elsewhere have consistently failed to demonstrate that age-based mandatory assessment results in reduced crash involvement for older drivers. However studies that have based their results upon either per-population or per-driver crash rates fail to take into account possible differences in driving activity. Because some older people maintain their driving licenses but rarely if ever drive, the proportion of inactive license-holders might be higher in jurisdictions without mandatory assessment relative to jurisdictions with periodic license assessment, where inactive drivers may more readily either surrender or lose their licenses. The failure to control for possible differences in driving activity across jurisdictions may be disguising possible safety benefits associated with mandatory assessment. The current study compared the crash rates of drivers in Melbourne, Australia, where there is no mandatory assessment and Sydney, Australia, where there is regular mandatory assessment from 80 years of age onward. The crash rate comparisons were based on four exposure measures: per population, per licensed driver, per distance driven, and per time spent driving. Poisson regression analysis incorporating an offset to control for inter-jurisdictional road safety differences indicated that there was no difference in crash risk for older drivers based on population. However drivers aged 80 years and older in the Sydney region had statistically higher rates of casualty crash involvement than their Melbourne counterparts on a per license issued basis (RR: 1.15, 1.02–1.29, p = 0.02) and time spent driving basis (RR: 1.19, 1.06–1.34, p = 0.03). A similar trend was apparent based on distance travelled but was of borderline statistical significance (RR: 1.11, 0.99–1.25, p = 0.07). Collectively, it can be inferred from these findings that mandatory license re-testing schemes of the type evaluated have no demonstrable road safety benefits overall. Further research to resolve this on-going policy debate is discussed and recommended.

Improving Visual Attention in Older Drivers

Changes in visual attention which occur with normal aging have been shown to be predictive of crash risk in older drivers (Ball, Owsley, Sloane, Roenker, &amp; Bruni, 1993; Owsley et al., 1998). The purpose of this study was to determine whether visual attention skills of older drivers were amenable to training. Participants were 40 volunteers aged 60 to 81. Following an initial visual attention assessment, 20 participants assigned to the training group completed five 30-minute visual attention training sessions. The remaining 20 participants were assigned to a control group. Following the training interval all participants once again completed a visual attention assessment. Results: At postesting, participants whose initial scores were poorest, and who received visual attention training achieved scores similar to those of participants with the best initial scores, while the control group members showed significantly smaller improvements.

Visual risk factors for crash involvement in older drivers with cataract.

The Impact of Cataracts on Mobility project has previously demonstrated that older drivers with cataract have an elevated risk of motor vehicle collision. To examine what types of visual impairment serve as a basis of the increased crash risk of older drivers with cataract. A cross-sectional analysis was performed on 274 older drivers with cataract and 103 older drivers free of cataract recruited through 12 eye care clinics for the purposes of the Impact of Cataracts on Mobility project, a prospective study on driving mobility in older adults with cataract. Tests measured visual acuity, contrast sensitivity, and disability glare for each eye separately using habitual distance correction. The dependent variable was involvement in at least 1 state-recorded, at-fault vehicle crash during the 5 years prior to study enrollment. Logistic regression evaluated associations (odds ratios [ORs]) between visual function and crash involvement. Better and worse eye models defined on the basis of visual acuity were developed. Associations between each type of visual function and crash involvement were adjusted for age, sex, driving exposure, cognitive status, and other types of visual function. For both the better and worse eye models, contrast sensitivity was independently associated with crash involvement, whereas visual acuity and disability glare were not. Drivers with a history of crash involvement were 8 times more likely to have a serious contrast sensitivity deficit in the worse eye (defined as a Pelli-Robson score of 1.25 or less) than those who were crash-free (OR = 7.86; 95% confidence interval [CI], 1.55-39.79); this association was weaker for the better eye but still statistically significant (OR = 3.78; 95% CI, 1.15-12.48). Crash-involved drivers were 6 times more likely to have severe contrast sensitivity impairment in both eyes (OR = 5.78; 95% CI, 1.87-17.86) than crash-free drivers. A severe contrast sensitivity deficit in only 1 eye was still significantly associated with crash involvement (OR = 2.70; 95% CI, 1.16-6.51). Severe contrast sensitivity impairment due to cataract elevates at-fault crash risk among older drivers, even when present in only 1 eye.

A traffic sign recognition test can discriminate between older drivers who have and have not had a motor vehicle crash.

To determine whether a Traffic Sign Recognition Test (TSRT) can identify older drivers who recently had a motor vehicle crash (MVC). Retrospective, matched, case-control study. Licensed drivers in Galveston, Texas. 60 crash and 60 control subjects matched for age and gender. Cases were identified from accident records. Controls were selected from a randomized list of licensed drivers in Galveston. Folstein Mini-Mental State Examination (MMSE) and the TSRT. A TSRT significantly distinguished between case and control groups (P = .01). The MMSE did not (P = .61). A TSRT predicted MVC in a multivariate analysis controlling for education, MMSE score, race/ethnicity, and mileage driven/year (odds ratio = 0.88, 95% confidence interval = 0.77-1.00). A TSRT successfully identifies older drivers with a recent MVC, but the test lacks sensitivity and specificity. A prospective study is needed to further delineate the TSRT's usefulness in predicting crash risk in older drivers.