Can a Cognitive–Perceptual–Physical Battery Predict Driving Competence for People With Mild Cognitive Impairments? A Pilot Study

PURPOSE: Driving safety is often a concern for people with mild cognitive impairment (MCI) and their families, even if no accidents have happened. However, preemptive driving cessation can lead to decreased activities, social participation, and quality of life. Off-road and on-road assessments compose driving evaluation. Off-road tests evaluate driving-related skills, including cognition, visual perception, and physical function. To date, no consensus on predictive off-road tests exists; on-road assessment is still recommended. In this study, we used comprehensive driving assessments to explore the similarities and differences between the performance of an MCI group and a healthy group in simulated on-road driving exams and off-road tests.

DESIGN: The study involved both a descriptive and an exploratory research design. We recruited 10 drivers with a confirmed diagnosis and another 10 healthy adults without subjective complaints about cognitive decline. Both groups were regular drivers, were age 50 yr and above, and reported no driving difficulties.

METHOD: The participants completed physical screening (range of motion testing, manual muscle testing, rapid pace walk test) and then a battery of cognitive–perceptual assessments, including the Mini-Mental State Examination, digit backward test, clock drawing test (CDT), Loewenstein Occupational Therapy Cognitive Assessment, Useful Field of Vision (UFOV), and Color Trail Test (CTT) Parts 1 and 2. Participants also drove a dual-control vehicle in a driving school and completed a simulated driving license assessment with a driving instructor and one or two occupational therapists in the car. The exam included turns, parallel parking, backup parking, responses to road signs, and so forth. Participants completed two trial runs before testing. Descriptive statistics were used to examine demographic data and on-road assessment results. Mann–Whitney U test was used to compare the off-road test results for the MCI and healthy groups and also of the pass and fail groups in the on-road assessment. Spearman’s rank correlation coefficient was used to see if a correlation existed between results of off-road tests and the on-road assessment.

RESULTS: No significant differences existed in age and gender in the two groups, but education level was higher in the control group. The MCI group performed worse in off-road tests than the control group. Only 35% of participants passed the simulated driving exams (50% of the control group, 20% of the MCI group); this meant that some participants with MCI and control participants could still drive. In addition, no significant difference existed in off-road test results between the pass and fail groups. However, scores on the CTT–2 (p = .081) and UFOV Subtest 2 (p = .056) showed a trend toward significance, and UFOV Subtest 2 (r = –.457, p = .043) and CDT time (r = .599, p = .005) were correlated with on-road assessment scores, meaning that visuocognitive assessments may be useful in driving evaluation.

CONCLUSION: The results indicate that some people with MCI can still drive, as can healthy older adults. Because none of the participants reported driving difficulties or a history of repeated traffic accidents, the low rate of passing suggests that performance on a driving license exam in a driver school may not be a good predictor of real-world driving abilities. Future study should use a realistic on-road assessment. In addition, visuocognitive assessments may play an important role in differentiating passed from failed drivers in on-road assessment. More participants are needed to confirm this study’s results.

IMPACT STATEMENT: Driving evaluation is one important occupational therapy domain. This study provided empirical evidence regarding the design of driving evaluation in people with MCI.

References

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