Desiree N. Lanford

Predictability of clinical assessments for driving performance

PROBLEM As the number of older drivers grows, it is increasingly important to accurately identify at-risk drivers. This study tested clinical assessments predictive of real-time driving performance. METHOD Selected assessment tools considered important in the identification of at-risk older drivers represented the domains of vision, cognition, motor performance, and driving knowledge. Participants were administered the battery of assessments followed by an on-road test. A univariate analysis was conducted to identify significant factors (<.05) to be included in a multivariate regression model. RESULTS Assessments identified as independently associated with driving performance in the regression model included: FACTTM Contrast sensitivity slide-B, Rapid Pace Walk, UFOV rating, and MMSE total score. DISCUSSION The domains of vision, cognitive, and motor performance were represented in the predictive model. SUMMARY Due to the dynamic nature of the driving task, it is not likely that a single assessment tool will identify at risk drivers. IMPACT ON INDUSTRY By standardizing the selection of clinical assessments used in driving evaluations, practitioners should be able to provide services more efficiently, more objectively, and more accurately to identify at-risk drivers.

Useful Field of View as a Reliable Screening Measure of Driving Performance in People With Parkinson's Disease: Results of a Pilot Study

Purpose: To determine the correlations of the Useful Field of View (UFOV), compared to other clinical tests of Parkinsons disease (PD); vision; and cognition with measures of on-road driving assessments and to quantify the UFOVs ability to indicate passing/failing an on-road test in people with PD. Methods: Nineteen randomly selected people with idiopathic PD, mean age = 74.8 (6.1), 14 (73.7%) men, 18 (94.7%) Caucasians, were age-matched to 104 controls without PD. The controls had a mean age of 75.4 (6.4), 59 (56.7%) men, 96 (92.3%) Caucasians. Both groups were referred for a driving evaluation after institutional review board approval. Results: Compared to neuropsychological and clinical tests of vision and cognition, the UFOV showed the strongest correlations (r > .75, p < 0.05) with measures of failing a standardized road test and number of driving errors. Among PD patients, the UFOV Risk Index score of 3 (range 1–5) was established as the optimal cutoff value for passing the on-road test, with sensitivity 87 percent and specificity 82 percent, AUC = 92 percent (SE 0.61, p = .002). Similarly, the UFOV 2 (divided attention) optimum cutoff value is 223 ms (range 16–500 ms), sensitivity 87.5 percent, specificity 81.8 percent, AUC = 91 percent (SE 0.73, p = .003). The UFOV 3 (selected attention) optimal cutoff value is 273 ms (range 16–500 ms), sensitivity 75 percent, specificity 72.7 percent, AUC = 87 percent (SE 0.81, p = .007). Conclusion: In this pilot study among PD patients, the UFOV may be a superior screening measure (compared to other measures of disease, cognition, and vision) for predicting on-road driving performance but its rigor must be verified in a larger sample of people with PD.

Predicting older driver on-road performance by means of the useful field of view and trail making test part B

The Useful Field of View(®) (UFOV) and Trail Making Test Part B (Trails B) are measures of divided attention. We determined which measure was more accurate in predicting on-road outcomes among drivers (N = 198, mean age = 73.86, standard deviation = 6.05). Receiver operating characteristic curves for the UFOV (Risk Index [RI] and Subtests 1-3) and Trails B significantly predicted on-road outcomes. Contrasting Trails B with the UFOV RI and subtests, the only difference was found between the UFOV RI and Trails B, indicating the UFOV RI was the best predictor of on-road outcomes. Misclassifications of drivers totaled 28 for the UFOV RI, 62 for Trails B, and 58 for UFOV Subtest 2. The UFOV RI is a superior test in predicting on-road outcomes, but the Trails B has acceptable accuracy and is comparable to the other UFOV subtests.

MMSE as a predictor of on-road driving performance in community dwelling older drivers.

Screening tools such as the MMSE have been used extensively in driving research studies to determine mild cognitive impairment or dementia. While some studies have shown the MMSE to correlate with driving performance, few studies have shown the predictive validity of the MMSE in determining on-road performance. In a sample of 168 community dwelling older adults, including 20 with Parkinsons disease (PD), the primary objective was to determine the validity of the MMSE to predict pass/fail outcomes of an on-road driving test using receiver operating characteristics curves. The area under the curve (AUC), an index of discriminability, for the total sample was .654, 95% CI=0.536-0.772, p=.009. Meanwhile, the AUC for the PD group was 0.791, 95% CI=0.587-0.996, p=.036. The total sample showed statistically significant yet poor predictive validity. However, the PD group showed statistically significant and good predictive validity of the MMSE to predict pass/fail outcomes on the road test, but caution is warranted as the confidence intervals are wide (due to small sample) and the positive and negative predictive values are less than desirable due to the associated error. The findings show that using the current cut-off point of ≤24 on the MMSE is not adequately sensitive to predict on-road performance in both community dwelling older drivers and in drivers with PD. This study offers strong evidence to support the current best practice of not using the MMSE in isolation to predict on-road performance.

Gender differences among older drivers in a comprehensive driving evaluation

Research studies typically consider older drivers as a homogenous group and do not report on the influence of gender on driving performance. Prior studies report that females are over-represented in crashes compared to males, caused by errors of yielding, gap acceptance, and speed regulation, all of which are assessed in a comprehensive driving evaluation (CDE). In a sample of 294 community dwelling older drivers, we examined and compared specific and total driving errors of both genders, and determined predictors of gender-specific driving errors and pass/fail outcomes who completed a CDE assessed by a certified driving rehabilitation specialist. No differences in specific or total number of driving errors on the CDE were found between older males (Mean age 73.4±6.0) and older females (Mean age 73.8±5.7). Education, days of driving, Useful Field of View™ (UFOV), Rapid Paced Walk Test (RPW) and the Mini-Mental State Exam (MMSE) were all independent predictors of failing a road test for both genders (p<0.05). However, older females were 22% less likely than older males to fail an on-road test. Within group comparisons showed that older males and females >75 years were 3.2 and 3.5 times more likely to fail the on-road test compared to younger males and females (aged between 63 and 75), respectively. Our findings suggest that focusing on older old (75+) and old-old (85+) age groups may be more efficient for future investigations of driving performance.

Psychometrics of the self-report safe driving behavior measure for older adults.

We investigated the psychometric properties of the 68-item Safe Driving Behavior Measure (SDBM) with 80 older drivers, 80 caregivers, and 2 evaluators from two sites. Using Rasch analysis, we examined unidimensionality and local dependence; rating scale; item- and person-level psychometrics; and item hierarchy of older drivers, caregivers, and driving evaluators who had completed the SDBM. The evidence suggested the SDBM is unidimensional, but pairs of items showed local dependency. Across the three rater groups, the data showed good person (≥3.4) and item (≥3.6) separation as well as good person (≥.93) and item reliability (≥.92). Cronbachs α was ≥.96, and few items were misfitting. Some of the items did not follow the hypothesized order of item difficulty. The SDBM classified the older drivers into six ability levels, but to fully calibrate the instrument it must be refined in terms of its items (e.g., item exclusion) and then tested among participants of lesser ability.

Clinical Practice in Driving Rehabilitation

The purpose of this article is to describe the process of occupational therapy practice in a driving rehabilitation setting. The article focuses on the services delivered by Independence Drive, a University of Florida–affiliated program designed to support safe mobility among older drivers in North and Central Florida. The services offered in this program are described, including the theoretical foundation used in the program, establishment of referral relationships, evaluations, interventions, and a professional training program to increase the capacity of the profession in meeting the needs of older drivers.

The Impact of Intersection Design on the Driving Performance of Adults in the Recovery Phase of a Turn

Driving, an instrumental activity of daily living, requires safe person-environment interactions. The effectiveness (safety) of four United States Federal Highway Administration intersection design guidelines in the recovery phase of a turn was tested on older and younger adults. Using kinematics measures from an instrumented vehicle, drivers negotiating improved and unimproved intersections were examined in Gainesville, Florida. The findings from a 2 × 2 repeated measures ANOVA (within-subject variable = intersection condition: improved versus unimproved; between-subject variable = age: young versus old) yield support for three manoeuvres: extended receiving lane, right-turn channelisation with acceleration lane and left-turn offset, but not for no acute turn angle. One interaction effect (age x intersection) existed and age effects (favouring older drivers) appeared for three manoeuvres, yet showed little practical significance, suggesting that these design guidelines benefit older and younger drivers alike. This study informs occupational therapists that enhancements in the environment have an impact on safer driving, particularly at urban intersections. A replication of the concept of this study, that is, testing intersection design guidelines in the United Kingdom, may generate valuable information on the plausibility of environmental design guidelines and their effects on the driving performance of older and younger adults.

Driving Performance and Behaviors: A Comparison of Gender Differences in Parkinson's Disease

Objective: The primary objective of this study was to determine gender differences by comparing self-reported driving behaviors, clinical tests, and on-road driving performance in a cohort of men and women drivers with Parkinsons disease (PD). Methods: In this prospective observational study, we analyzed data of a convenience sample of 63 men (mean age = 70.9 ± 6.6 years) and 21 women (mean age 67.1 ± 7.3 years) with diagnosed PD. All participants underwent a comprehensive driving evaluation by a certified driving rehabilitation specialist. Results: On average, both men and women were active drivers (driving ∼4.6 times/week). A substantial proportion of both groups avoided driving at night (40% of men versus 46% of women), during rush hour, and in heavy traffic (36% of men versus 57% of women), although the differences were not significant. Both groups reported some avoidance behaviors: making left-hand turns (9.7% men versus 9.5% women), driving in the rain (12.9% men versus 19.0% women), or on the interstate/highway (14.3% men versus 7.7% women). With respect to driving performance, both groups were equally likely to fail the on-road test (42.6% men versus 42.9% women). Although men committed slightly more total driving errors compared to women, the differences were not statistically significant. Specific driving errors also did not differ by gender. Controlling for gender and disease severity, age was an independent predictor of total driving errors in men but not in women. Additionally, a cut-point of ≥2.5 on the modified Hoehn and Yahr was predictive of pass–fail outcomes in men when controlling for age. Conclusions: Our study shows preliminary evidence that few gender differences exist with respect to driving errors and overall driving performance. Future studies should better balance gender distribution by age in PD driving studies to determine whether there are indeed differences in driving performance between men and women.