Association of Functional Impairments and Co-Morbid Conditions with Driving Performance among Cognitively Normal Older Adults.

OBJECTIVES: To examine the relationship between key functional impairments, co-morbid conditions and driving performance in a sample of cognitively normal older adults.

DESIGN: Prospective observational study.

SETTING: The Knight Alzheimer's Disease Research Center, Washington University at St. Louis.

PARTICIPANTS: Individuals with normal cognition, 64.9 to 88.2 years old (N = 129), with a valid driver's license, who were currently driving at least once per week, and who had participated in longitudinal studies at the Knight Alzheimer's Disease Research Center.

MEASUREMENTS: Static visual acuity, contrast sensitivity, physical frailty measures, motor skills, total medical conditions, and the modified Washington University Road Test.

RESULTS: When controlling for age, race, gender, APOE, and education the total number of medical conditions was unassociated with both road test scores (pass vs. marginal + fail) and the total driver error count. There were marginal associations of our measure of physical frailty (p = 0.06) and contrast sensitivity score (p = 0.06) with total driving error count.

CONCLUSION: Future research that focuses on older adults and driving should consider adopting measures of physical frailty and contrast sensitivity, especially in samples that may have a propensity for disease impacting visual and/or physical function (e.g. osteoarthritis, Parkinson's, eye disorders, advanced age >80 years, etc.).