Kezia D. Awadzi

Comparison of Driving Errors Between On-the-Road and Simulated Driving Assessment: A Validation Study

Objective: Driving simulation provides a convenient and safe method for assessing driving behaviors. Many authors, however, agree that validation is a key component of any study that utilizes simulators to assess driving performance. The purpose of this study was to test driver response validity by discerning whether behavioral responses of drivers, as expressed by type and number of errors, are similar on the road and in the simulator. Methods: We replicated real-world intersections in our driving simulator (STISIM M500W; Systems Technology Inc.) and assessed the number and type of driving errors committed by the same 39 participants while negotiating a right and a left turn both on the road and in the simulator. Results: We found no significant interactions between the type of vehicle (road vs. simulator) and the type of turn (right versus left) for any of the driving errors, indicating that the same trends exist between driving errors made on the road and in the simulator and thus suggesting relative validity of the simulator. We also found no significant differences between the road and the simulator for lane maintenance, adjustment to stimuli, and visual scanning errors, indicating absolute validity for these types of errors. Conclusions: The findings suggest early support for external validity for our driving simulator, indicating that the results of assessing driving errors when negotiating turns in the simulator can be generalized or transferred to the road under the same testing conditions. A follow-up study with larger sample size is needed to establish whether driving performance in the simulator is predictive of driving performance on the road.

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.

Clinical Predictors of Older Driver Performance on a Standardized Road Test

Objectives. To determine the relationship between clinical variables (demographics, cognitive testing, comorbidities, and medications) and failing a standardized road test in older adults. Methods. Analysis of on-the road studies performed in optimal weather conditions, between January 1, 2005, and May 1, 2007. The standardized testing was held at the National Older Driver Research and Training Center (NODRTC), Florida, and included 127 adults aged 65 and older with current driver licenses, recruited by advertisement from the Gainesville, Florida, community. Measurements consist of demographics, self-reported medications and medical conditions, cognitive testing including Trail Making Part B, global rating score (pass/fail), and driver maneuver score (0–273, with 273 indicating perfect driving or zero errors). Results. A total of 127 older adults completed the protocol. Mean age was 74.8 years (SD = 6.3); 46.5% females. Mean time for Trail Making Part B was 114.3 seconds (SD of 83). Among the 127 drivers, the mean Sum of Maneuvers Score was 238.9 (SD of 25.0) and 24 (19%) failed the driver test. Odds ratio estimates for failing the test included advanced age (6.7, 95% CI 2.2 to 19.8), presence of a neurological disease (2.8, 95% CI 1.2 to 6.5), and prolonged time to complete the Trail Making Part B cognitive test (2.5, 95% CI 1.0 to 5.9). Conversely, odds ratio estimates lowering the risk of failure included taking a non-diabetic hormonal medications (e.g., thyroid and estrogen drugs; 0.3, 95% CI .09 to 0.7) and having a musculoskeletal diagnosis (0.3, 95% CI .1 to 0.7). Conclusions. To our knowledge, this is the first study to examine the medical predictors of failing a standardized road test. Advanced age and prolonged time on Trail Making Part B were the two major predictors of test failure and a lower Sum of Maneuvers Score. Our study also found that having a neurological diagnosis (primarily cerebrovascular and Parkinsons disease) predicted test failure. Medications from neurological class also predicted a lower Sum of Maneuvers Score. Further study needs to be done to explain the apparent protective effect of musculoskeletal conditions and hormonal medications.

Literature Review on Older Adult Gender Differences for Driving Self-regulation and Cessation

Researchers are calling for increased studies with regard to differences between older men and women drivers. This literature review focuses on gender comparisons for self-regulation of driving and driving cessation. We reviewed 20 articles and assigned levels of evidence. Seven studies were level II (eg, prospective cohort) and 13 were level III (eg, cross-sectional). Subsequently, 5 evidence-based recommendations were made to address gender-specific needs of older men and women. Additional research is needed to clarify gender patterns for self-regulation and cessation and increase the level of evidence supporting gender-specific driving interventions.

Systematic Literature Review and Model for Older Driver Safety

Using the Precede-Proceed Model of Health Promotion (PPMHP) and an etiological systematic literature review, we examined the risk/protective factors of older driver safety in the United States. We described key features of this literature review and developed a structural model illustrating the prevalence of risk/protective factors in the health domain (63%) and in other PPMHP domains (environment 20%; behavior and lifestyle 10%; predisposing 1%; reinforcing 3%, enabling 2%; health education 2%). This model, a first step in synopsizing and quantifying these risk/protective factors, informs rehabilitation professionals of their etiology and prevalence, affords opportunities for multidisciplinary research, and lays the foundation for intervention planning.

Determinants of Older Driver Safety from a Socioecological Perspective

Older driver safety is a complex phenomenon, extending beyond the person level to multiple system characteristics, such as epidemiologic, environment, and policy. Studying multiple factors in older driver safety requires the use of an integrated socioecological approach. In a cross-sectional design, we used a public health model and the 2003 General Estimates System database to determine main risk factors and their measures of association in the presence or absence of injury among older adults involved in motor vehicle accidents. Compared to the findings of the existing literature, participants demonstrated similar person-level crash-related injury characteristics. However, the socioecological model elucidated the importance of environment-level and vehicle-level factors as significant determinants of older driver safety.