Performance-based driving evaluation of the elderly driver: safety, reliability, and validity

BACKGROUND

Our driving population is aging and faces increased risk for injury and death from motor vehicle crashes. Clinicians are often asked to judge the driving safety of their patients without adequate guidelines. This article describes the development of a systematic performance-based road test for measuring driving skills of elderly drivers and its correlation with cognitive measures.

METHODS

This was a prospective, masked, observational study in which a driving instructor's global scores ("criterion standard") and cognitive test scores were correlated with research driving scores created by two independent research raters sitting in the back seat of the care during each driving test. A convenience sample of 30 licensed drivers with a broad range of cognitive skills, over age 60, were studied on a closed course and in traffic.

RESULTS

Statistically significant correlations were observed between the "criterion standard" and closed course scores (r = .35, p < .05) and between the "criterion standard" and in-traffic scores (r = .64, p < .01). Significant correlations were obtained between in-traffic and cognitive test scores, e.g., Mini-Mental State Exam (r = .72, p < .01). Inter-rater reliability on the closed course was .84 and on the in-traffic component was .74. Internal consistency for the closed course was .78 and for in-traffic was .89.

CONCLUSION

This study documented the safety, reliability, and validity of a systematic road test for elderly drivers with a range of cognitive skills. Larger studies are needed to determine the cognitive factors that independently predict driving performance.

Predictors of Driving Ability Following Stroke: A Systematic Review

BACKGROUND AND PURPOSE

The objective of this review is to identify the most consistent predictors of driving ability post stroke.

METHOD

A computerized search of numerous databases from 1966 forward was completed. Measured outcomes included voluntary driving cessation or results of on-road driving evaluation. Studies were evaluated using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

17 eligible studies were identified. The most useful screening tests were tests assessing cognitive abilities. These included the Trail Making A and B tests, the Rey-Osterreith Complex Figure Design, and the Useful Field of View Test.

CONCLUSION

Cognitive tests that assess multiple cognitive domains relevant to driving appear to have the best reproducibility in predicting fitness to drive in stroke patients.

Executive functions in the evaluation of accident risk of older drivers

The main objective of these studies was to analyse the difference in driving attitude and aptitude, between two groups of elderly male drivers (65 years or more), one being accident-free and the second having three accidents or more in the last 5 years. The first study compared the driving habits of 90 older accident-free drivers with 90 drivers having a history of accidents. The second study, on a subgroup of 60 of the original 180 subjects (30 accident-free and 30 having accidents), compared cognitive function, with particular emphasis on executive functions as measured by neuropsychological tests, and attitude and self-reported driving behaviour. The results show that elderly drivers having a history of accidents, compared to the control group: (1) have poorer performance on the four cognitive measurements of executive functions; (2) report to have more prudent behaviour on the road (e.g., reducing their speed); and (3) have the intention to adopt less risky driving behaviour. This study suggests that a subgroup of the older driver population has cognitive problems and driving disabilities that cannot be compensated by apparently more careful behaviour on the road. The results confirm the importance of proper assessment of cognitive processes and underscore the potential of measuring executive functions for the evaluation of driving competence of elderly persons.

Driving simulator performance in patients with sleep apnea

Although previous studies have shown that patients with obstructive sleep apnea have a higher automobile crash rate than normal subjects, objective measurements of driving performance in patients with sleep apnea have not been reported. Therefore, we compared the driving performance of subjects with untreated, severe sleep apnea to that of control subjects on two driving simulators. Using a simulator with road films, six subjects with untreated, severe apnea performed worse than did a control group of seven normal subjects on both highway and city/rural driving (p less than 0.05). Using a personal computer program simulating a monotonous highway drive, 12 subjects with untreated sleep apnea performed worse than 12 control subjects. The patients with apnea hit a greater number of road obstacles during their 30-minute simulated drive than did the control subjects (44 +/- 52 in patients with apnea versus 9 +/- 7 in control subjects, p less than 0.05). Six patients with apnea hit fewer road obstacles after treatment with nasal continuous positive airway pressure (CPAP) than before treatment (29 +/- 19 before CPAP versus 13 +/- 8 after CPAP, p less than 0.05). We conclude that: (1) driving simulator performance of untreated subjects with severe obstructive sleep apnea is worse than that of control subjects; (2) driving simulator performance of subjects treated with nasal CPAP improves.

Effect of Cannabidiol and Δ9-Tetrahydrocannabinol on Driving Performance: A Randomized Clinical Trial

IMPORTANCE

Cannabis use has been associated with increased crash risk, but the effect of cannabidiol (CBD) on driving is unclear.

OBJECTIVE

To determine the driving impairment caused by vaporized cannabis containing Δ9-tetrahydrocannabinol (THC) and CBD.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, within-participants, randomized clinical trial was conducted at the Faculty of Psychology and Neuroscience at Maastricht University in the Netherlands between May 20, 2019, and March 27, 2020. Participants (N = 26) were healthy occasional users of cannabis.

INTERVENTIONS

Participants vaporized THC-dominant, CBD-dominant, THC/CBD-equivalent, and placebo cannabis. THC and CBD doses were 13.75 mg. Order of conditions was randomized and balanced.

MAIN OUTCOMES AND MEASURES

The primary end point was standard deviation of lateral position (SDLP; a measure of lane weaving) during 100 km, on-road driving tests that commenced at 40 minutes and 240 minutes after cannabis consumption. At a calibrated blood alcohol concentration (BAC) of 0.02%, SDLP was increased relative to placebo by 1.12 cm, and at a calibrated BAC of 0.05%, SDLP was increased relative to placebo by 2.4 cm.

RESULTS

Among 26 randomized participants (mean [SD] age, 23.2 [2.6] years; 16 women), 22 (85%) completed all 8 driving tests. At 40 to 100 minutes following consumption, the SDLP was 18.21 cm with CBD-dominant cannabis, 20.59 cm with THC-dominant cannabis, 21.09 cm with THC/CBD-equivalent cannabis, and 18.28 cm with placebo cannabis. SDLP was significantly increased by THC-dominant cannabis (+2.33 cm [95% CI, 0.80 to 3.86]; P < .001) and THC/CBD-equivalent cannabis (+2.83 cm [95% CI, 1.28 to 4.39]; P < .001) but not CBD-dominant cannabis (-0.05 cm [95% CI, -1.49 to 1.39]; P > .99), relative to placebo. At 240 to 300 minutes following consumption, the SDLP was 19.03 cm with CBD-dominant cannabis, 19.88 cm with THC-dominant cannabis, 20.59 cm with THC/CBD-equivalent cannabis, and 19.37 cm with placebo cannabis. The SDLP did not differ significantly in the CBD (-0.34 cm [95% CI, -1.77 to 1.10]; P > .99), THC (0.51 cm [95% CI, -1.01 to 2.02]; P > .99) or THC/CBD (1.22 cm [95% CI, -0.29 to 2.72]; P = .20) conditions, relative to placebo. Out of 188 test drives, 16 (8.5%) were terminated due to safety concerns.

CONCLUSIONS AND RELEVANCE

In a crossover clinical trial that assessed driving performance during on-road driving tests, the SDLP following vaporized THC-dominant and THC/CBD-equivalent cannabis compared with placebo was significantly greater at 40 to 100 minutes but not 240 to 300 minutes after vaporization; there were no significant differences between CBD-dominant cannabis and placebo. However, the effect size for CBD-dominant cannabis may not have excluded clinically important impairment, and the doses tested may not represent common usage.

TRIAL REGISTRATION

EU Clinical Trials Register: 2018-003945-40.

Traffic-related injury prevention interventions for low-income countries

Traffic-related injuries have become a major public health concern worldwide. However, unlike developed or high-income countries (HICs), many developing or low-income countries (LICs) have made very little progress towards addressing this problem. Lack of the progress in LICs is attributable, in part, to their economic situation in terms of their governments' lack of resources to invest in traffic safety, cultural beliefs regarding the fatalism of injuries, competing health problems particularly with the emergence of HIV/AIDS, distinctive traffic mixes comprising a substantial number of vulnerable road users for whom less research has been done, low literacy rates precluding motorists to read and understand road signs, and peculiar political situations occasionally predominated by dictatorship and non-democratic governments. How then can LICs tackle the challenge of traffic safety from the experiences of HICs without reinventing the wheel? This paper reviews selected interventions and strategies that have been developed to counter traffic-related injuries in HICs in terms of their effectiveness and their applicability to LICs. Proven and promising interventions or strategies such as seat belt and helmet use, legislation and enforcement of seat belt use, sidewalks, roadway barriers, selected traffic-calming designs (e.g., speed ramps/bumps), pedestrian crossing signs combined with clearly marked crosswalks, and public education and behavior modification targeted at motorists are all feasible and useable in LICs as evidenced by data from many LICs. While numerous traffic-related injury policy interventions and strategies developed largely in HICs are potentially transferable to LICs, it is important to consider country-specific factors such as costs, feasibility, sustainability, and barriers, all of which must be factored into the assessment of effectiveness in specific LIC settings. Almost all interventions and strategies that have been proven effective in HICs will need to be evaluated in LICs and particular attention paid to the effectiveness of enforcement measures. It behooves LIC governments, however, to ensure that only standard, approved safety devices like helmets are imported into their countries. Additionally, LICs may need to improvise and innovate in the traffic safety technology transfer.

Decreased driving ability in people with Parkinson's disease

BACKGROUND

Driving is a complex form of activity involving especially cognitive and psychomotor functions. These functions may be impaired by Parkinson's disease. The relation between Parkinson's disease and driving ability is still obscure and clinicians have to make decisions concerning the driving ability of their patients based on insufficient information. Until now no studies have compared different methods for evaluating the driving ability of patients with Parkinson's disease.

METHODS

The driving ability of 20 patients with idiopathic Parkinson's disease and 20 age and sex matched healthy control subjects was evaluated by a neurologist, psychologist, vocational rehabilitation counsellor, and driving instructor using a standard 10 point scale. The patients and controls also evaluated their own driving ability. Cognitive and psychomotor laboratory tests and a structured on road driving test were used for evaluating the subjects' driving ability.

RESULTS

The patients with Parkinson's disease performed worse than the controls both in the laboratory tests and in the driving test. There was a high correlation between the laboratory tests and driving test both in the patient group and in the control group. Disease indices were not associated with the driving test. The neurologist overestimated the ability of patients with Parkinson's disease to drive compared with the driving ability evaluated by the structured on road driving test and with the driving related laboratory tests. Patients themselves were not capable of evaluating their own ability reliably.

CONCLUSION

Driving ability is greatly decreased in patients with even mild to moderate Parkinson's disease. The evaluation of patients' driving ability is very difficult to carry out without psychological and psychomotor tests and/or a driving test.

Predictive validity of driving-simulator assessments following traumatic brain injury: a preliminary study

OBJECTIVE

To evaluate whether driving simulator and road test evaluations can predict long-term driving performance, we conducted a prospective study on 11 patients with moderate to severe traumatic brain injury. Sixteen healthy subjects were also tested to provide normative values on the simulator at baseline.

METHOD

At their initial evaluation (time-1), subjects' driving skills were measured during a 30-minute simulator trial using an automated 12-measure Simulator Performance Index (SPI), while a trained observer also rated their performance using a Driving Performance Inventory (DPI). In addition, patients were evaluated on the road by a certified driving evaluator. Ten months later (time-2), family members observed patients driving for at least 3 hours over 4 weeks and rated their driving performance using the DPI.

RESULTS

At time-1, patients were significantly impaired on automated SPI measures of driving skill, including: speed and steering control, accidents, and vigilance to a divided-attention task. These simulator indices significantly predicted the following aspects of observed driving performance at time-2: handling of automobile controls, regulation of vehicle speed and direction, higher-order judgment and self-control, as well as a trend-level association with car accidents. Automated measures of simulator skill (SPI) were more sensitive and accurate than observational measures of simulator skill (DPI) in predicting actual driving performance. To our surprise, the road test results at time-1 showed no significant relation to driving performance at time-2.

CONCLUSION

Simulator-based assessment of patients with brain injuries can provide ecologically valid measures that, in some cases, may be more sensitive than a traditional road test as predictors of long-term driving performance in the community.

The driving habits of adults aged 60 years and older

OBJECTIVES

We describe the driving habits of adults aged 60 years and older who were interviewed in the context of a community survey focused on mental disturbances. Our goal was to identify clinical cues that might signal driving difficulty in older adults who might present to the primary care physician for health care.

DESIGN

A population-based survey.

SETTING

Continuing participants in a follow-up study of community-dwelling adults who were living in East Baltimore in 1981.

PARTICIPANTS

Subjects were 1920 continuing participants of the Baltimore sample of the Epidemiologic Catchment Area Program; 589 were aged 60 years and older and provided information on driving habits.

MEASUREMENTS

Respondents were asked about their driving status: had they made adaptations to driving and had they experienced any adverse driving events in the 2 years before the interview. Driving behaviors were assessed in relation to chronic disease, sensory impairment, functional status, and mental status.

RESULTS

Former drivers were more likely to be older, female, and nonwhite. Diabetes, vision impairment, functional impairment, and making an error on the copy design task of the Mini-Mental State Examination (MMSE) were associated with no longer driving. Women were more likely to report having made adaptations to driving, as were persons with heart disease, arthritis, vision impairment, and those who made an error on the copy design task of the MMSE. Heart disease and hearing impairment were associated with report of an adverse driving event. In multivariate models that included terms for potentially influential characteristics such as age, gender, and miles driven, only the copy design task was associated with driving status, and only heart disease was associated with driving adaptation and adverse driving events.

CONCLUSION

Simple tests that tap visuospatial ability, such as the copy design task of the MMSE, may warrant additional study for use in driving assessment of older adults in primary care. The results underscore the importance of making an inquiry about driving as a separate and independent component of functional assessment.

Can novice drivers be trained to scan for information that will reduce their likelihood of a crash?

Sixteen year old drivers are involved in 10.3 fatal crashes per 100 million vehicle miles, a rate almost double that of 18 year olds and almost eight times that of 45-64 year olds, who are the safest group of drivers. Crash rates are particularly higher during the first month of licensure and decline rapidly for about six months and 1000 miles and then much more slowly for at least two years, consistent with a typical learning curve. Research indicates that drivers who have their learner's permit or are just newly licensed have particular difficulties identifying areas of a scenario from which hidden risks could emerge. Standard driver education programs do not appear to address these difficulties adequately. This suggests that some alternative form of driver training could reduce the crashes, either in the classroom or on the road. A PC based program designed to teach drivers to recognize risks early on is shown to improve their awareness of hazards, both on an advanced driving simulator and on the road.

The relationship between cognitive/neuropsychological factors and car driving performance in older adults

OBJECTIVES

Because demographic changes produce a society with a growing number of older people, seniors constitute the fastest growing segment of car drivers. The objective of this research project was to identify cognitive factors related to driving problems in older adults. A top-down approach has been used, testing theory-driven hypotheses.

DESIGN

Correlational study.

SETTING

Fitness-to-Drive Assessment Centre of the Belgian Road Safety Institute.

PARTICIPANTS

The research sample consisted of 84 car drivers aged over 65 years, who were referred for a general fitness-to-drive evaluation.

MEASUREMENTS

The relations between seven specific neuropsychological tests and self-reported accidents were investigated. Furthermore, the relations between these same tests and a road test, independently assessed using a detailed evaluation grid, were analyzed in depth. These analyses were followed by stepwise multiple regression analyses.

RESULTS

In a stepwise regression model, four neuropsychological tests could account for 64% of the variance of the score on the road test. Moreover, it could be demonstrated that specific cognitive subskills share common variance with specific real-world situations. However, neuropsychological tests could explain only 19% of the variance of self-reported at fault car accidents.

CONCLUSIONS

The initial results of this study indicate the relevance of a cognitive/neuropsychological approach to the driving ability of older people. However, the link with accident risk seems more complex. Consequently, neuropsychological screening procedures are in need of a broader perspective to prevent an overemphasis on unidimensional screening procedures focusing mainly on deficit and less on capacities for safe behavior.

Driving and dementia: a review of the literature

The purpose of this article is to review the literature on the ability of individuals with dementia to drive an automobile. Based on a review of the literature, several factors were identified that may be useful in differentiating between people with dementia who presently remain safe drivers from those who have progressed to impaired driving. These factors include disease duration and severity, sex, patient self-assessment, family assessment, neuropsychological measures, findings on road evaluations, and driving simulator testing. The approach of the physician to driving and dementia is addressed, including in-office screening, referral for on-road driving assessments, and the potential for physician reporting to state agencies.

Driving Evaluation Practices of Clinicians Working in the United States and Canada

OBJECTIVE

To determine off-road and on-road driving evaluation practices of clinicians in the United States and Canada who assess individuals with disabilities for fitness to drive.

PARTICIPANTS

Participants were 114 clinician attendees at the 2003 annual Association of Driver Educators for the Disabled with driving assessment experience ranging from 1 month to 25 years.

MEASURES

Information was elicited regarding the clinician, clientele, referral practices, and off-road and on-road driving evaluation practices and retraining practices using a self-administered questionnaire.

RESULTS

Participants were largely occupational therapists (68%) who worked in 42 different states and provinces. The most prevalent clientele were persons with traumatic brain injury (97%) and stroke (96%). Testing times greater than 60 min were common for both the off-road (61%) and on-road (49%) evaluations. Commonly performed off-road assessments included the Brake Reaction Timer; Trail Making Test, Parts A and B; and the Motor Free Visual Perception Test, used by 73%, 72%, and 66%, respectively; comprehensive computer-based driving evaluation was rare. Sixty-one percent indicated that all clients underwent on-road evaluation regardless of the off-road results. Finally, 78% used a standard driving route, whereas 24% used a scoring system to evaluate on-road driving.

CONCLUSION

Driving assessment in Canada and the United States is multidimensional and time-intensive. Although the domains being assessed are similar across clincians, specific off-road and on-road assessment practices vary greatly. The majority use nonstandardized on-road assessments.

Locus of control as moderator: an explanation for additive versus interactive findings in the demand-discretion model of work stress?

Research based on Karasek's (1979) model of work stress has produced conflicting results; although some evidence of the demand X discretion interactions predicted by the model has been reported, most studies have failed to demonstrate interactive effects in relation to mental health outcomes. The present article investigates locus of control (LOC) as a potential moderator of demand/discretion effects. In a sample of civil servants (N = 590), regression analyses demonstrated a three-way LOC X demand X discretion interaction (p less than .01) for affective distress, but not for absence frequency. In longitudinal data from student teachers (N = 147), a similar three-way interaction was observed (p less than .05). In this case, the result applied specifically to anxiety as an outcome, and not to social dysfunction. In each study, the form of the three-way interaction was such that demand and discretion combined interactively to predict outcome for externals (-1SD LOC), in a manner consistent with Karasek's predictions, whereas for internals (+1SD LOC) additive findings were obtained. The implications of these results are discussed with reference to the demand-discretion model, and to the issues of stressor-outcome specificity raised by Broadbent (1985).

The use of a cognitive battery to predict who will fail an on-road driving test

OBJECTIVES

There is a growing need to find a valid and reliable neuropsychological battery to screen out those people who are clearly unsafe to drive following brain injury or pathology, and thus alleviate the need to refer for an on-road assessment.

DESIGN

A battery of cognitive tests fine-tuned for their relevance to driving was examined in terms of its sensitivity and specificity for predicting who would fail an on-road test following brain injury or pathology.

METHOD

Performance on the battery was compared to the results of an on-road driving test in a consecutive series of 142 clients referred to a driving assessment centre following brain injury or pathology. The group represented diverse neurological conditions which affect brain functioning.

RESULTS

The overall accuracy rate of the battery in predicting a fail on-road was 92% and in predicting a pass on road was 71%. It was more accurate for those under 70 with 100% accuracy in predicting a fail on-road and 85% accuracy in predicting a pass on-road, but less accurate for those aged 70 or above with 85% accuracy in predicting a fail on-road and 37% accuracy in predicting a pass on-road.

CONCLUSION

The battery is a useful tool in helping to determine whether someone is safe to drive following brain injury but needs to be used with far more caution for the older driver.

Effectiveness of a visual attention retraining program on the driving performance of clients with stroke

OBJECTIVE

To compare the effectiveness of a visual attention retraining program using the Useful Field of View (UFOV) with a traditional visuoperception treatment program on the driving performance of clients with stroke.

DESIGN

Randomized controlled trial.

SETTING

Rehabilitation hospital located in Quebec, Canada.

PARTICIPANTS

Ninety-seven individuals referred for driving evaluation after a stroke.

INTERVENTIONS

Participants were randomized to receive 20 sessions of either UFOV training of visual processing speed, divided attention, and selective attention or traditional computerized visuoperception retraining.

MAIN OUTCOME MEASURES

Subjects were evaluated with an on-road driving evaluation, visuoperception tests, and the Test of Everyday Attention. An occupational therapist unaware of group assignment conducted all evaluations.

RESULTS

Eighty-four participants completed the outcome evaluation. There were no significant differences between groups on any of the outcome measures. There was, however, almost a 2-fold increase (52.4% vs 28.6%) in the rate of success on the on-road driving evaluation after UFOV training for subjects with right-sided lesions.

CONCLUSIONS

Rehabilitation that targets visual attention skills was not significantly more beneficial than traditional perceptual training in improving the outcome of an on-road driving evaluation. However, results suggest a potential improvement for subjects with right-sided lesions, indicating that training must target specific skills.

The relationship between performance on the standardised field sobriety tests, driving performance and the level of Δ9-tetrahydrocannabinol (THC) in blood

The consumption of Delta9-tetrahydrocannabinol (THC) as cannabis has been shown to result in impaired and culpable driving. Testing drivers for the presence of THC in blood is problematic as THC and its metabolites may remain in the blood for several days following its consumption, even though the drug may no longer have an influence on driving performance. In the present study, the aim was to assess whether performance on the standardised field sobriety tests (SFSTs) provides a sensitive measure of impaired driving behaviour following the consumption of THC. In a repeated measures design, 40 participants consumed cigarettes that contained either 0% THC (placebo), 1.74% THC (low dose) or 2.93% THC (high dose). For each condition, after smoking a cigarette, participants performed the SFSTs on three occasions (5, 55 and 105 min after the smoking procedure had been completed) as well as a simulated driving test on two occasions (30 and 80 min after the smoking procedure had been completed). The results revealed that driving performance was not significantly impaired 30 min after the consumption of THC but was significantly impaired 80 min after the consumption of THC in both the low and high dose conditions. The percentage of participants whose driving performance was correctly classified as either impaired or not impaired based on the SFSTs ranged between 65.8 and 76.3%, across the two THC conditions. The results suggest that performance on the SFSTs provides a moderate predictor of driving impairment following the consumption of THC and as such, the SFSTs may provide an appropriate screening tool for authorities that wish to assess the driving capabilities of individuals suspected of being under the influence of a drug other than alcohol.

Evaluation of neuropsychological function in patients with liver cirrhosis with special reference to their driving ability

Ability to drive an automobile was evaluated in 16 patients with well compensated liver cirrhosis. Four tests were performed, namely the emergency reaction test, the continuous emergency reaction test, the signal confirmation test and the accelerator reaction test. Test scores were compared to those of a group of age-matched healthy volunteers. 31% of patients were found to be unfit to drive. Alcoholic cirrhotics fared as poorly as non-alcoholic cirrhotics. In patients with subclinical hepatic encephalopathy (defined by neuropsychologic testing), 44% were unfit to drive. Routine testing of cirrhotic patients for ability to drive could have a major impact on motor vehicle accident rates.

Lower-extremity function for driving an automobile after operative treatment of ankle fracture

BACKGROUND

The purpose of this study was to determine when patients recover the ability to safely operate the brakes of an automobile following operative repair of an ankle fracture.

METHODS

A computerized driving simulator was developed and tested. Eleven healthy volunteers were tested once to establish normal mean values (Group I), and a group of thirty-one volunteers with a fracture of the right ankle were tested at six, nine, and twelve weeks following operative repair (Group II). The subjects were tested with a series of driving scenarios (city, suburban, and highway). Scores on the Short Form Musculoskeletal Assessment were recorded at six, nine, and twelve weeks and were compared with the results of the driving test. We investigated the effect of the time of the visit and of the testing condition on the braking times.

RESULTS

The total braking time was 1079 msec for Group I and 1330, 1172, and 1160 msec for Group II at six, nine, and twelve weeks, respectively, postoperatively (p = 0.0094). The total braking time consistently improved for each of the driving scenarios at each successive data point (p = 0.05). The increase in the total braking time at six weeks meant an increase in the distance traveled by the automobile before braking of 22 ft (6.7 m) at 60 mph (96.6 km/hr), and the increase at nine weeks meant an increase of 8 ft (2.4 m) at 60 mph. The functional outcome improved at each successive visit, although no significant association was found between the functional scores and normalization of total braking time.

CONCLUSION

By nine weeks, the total braking time of patients who have undergone fixation of a displaced right ankle fracture returns to the normal, baseline value.

Driving following traumatic brain injury: prevalence, exposure, advice and evaluations

Survivors of traumatic brain injury often have long-term sensory, cognitive and motor deficits that may impair vehicle operation. However, relatively little is known about the driving status and driving characteristics of brain injury survivors. To better understand driving following traumatic brain injury, a survey of driving status, driving exposure, advice received about driving and evaluations of driving competency was administered to a convenience sample of traumatic brain injury survivors (n = 83). The majority of survey participants had experienced either moderate or severe traumatic brain injuries based on the Glasgow Coma Scale. A total of 60% of the survey participants reported that they were currently active drivers. Most individuals (> 60%) who had returned to driving reported driving every day and more than 50 miles per week. Traumatic brain injury survivors frequently received advice about driving from family members, physicians or non-physician health care professionals, but over half (63%) had not been professionally evaluated for driving competency. The presence of high driving exposure, coupled with a lack of widespread driving fitness testing, suggests that some traumatic brain injury survivors have characteristics that may evaluate their risk for vehicle crashes. However, subsequent prospective studies that directly assess driver safety will be needed to confirm this possibility.

Driving after cerebral damage: a model with implications for evaluation

Evaluation of the ability of cerebrally injured patients to return to driving is an important task for rehabilitation specialists. These evaluations require predictively valid methods of assessment based on identification of relevant skills and abilities. The present study tested a hypothetical model for driving after cerebral injury and determined its use in evaluating fitness to drive. Thirty-five patients with cerebral damage due to head injury or cerebrovascular accident participated in the study. All were administered (a) a predriver evaluation, that is, a battery of neuropsychological tests chosen a priori to test the model, (b) a simulator evaluation, and (c) a behind-the-wheel evaluation consisting of driving on a protected course and in traffic. The results showed that 93% of the driving outcome in traffic was explained cumulatively by findings from the predriver and simulator evaluations as well as from behavioral and operational measures during evaluation on the protected lot. These results supported the predictive validity of the model and are discussed in terms of methodology for evaluation of return to driving.

Visual and cognitive predictors of driving safety in Parkinson's disease patients

This study assessed the clinical utility of contrast sensitivity (CS) relative to attention, executive function, and visuospatial abilities for predicting driving safety in participants with Parkinson's disease (PD). Twenty-five, non-demented PD patients completed measures of contrast sensitivity, visuospatial skills, executive functions, and attention. All PD participants also underwent a formal on-road driving evaluation. Of the 25 participants, 11 received a marginal or unsafe rating on the road test. Poorer driving performance was associated with worse performance on measures of CS, visuospatial constructions, set shifting, and attention. While impaired driving was associated with a range of cognitive and visual abilities, only a composite measure of executive functioning and visuospatial abilities, and not CS or attentional skills, predicted driving performance. These findings suggest that neuropsychological tests, which are multifactorial in nature and require visual perception and visual spatial judgments are the most useful screening measures for hazardous driving in PD patients.