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.).