Car Accidents Associated with Physical Frailty and Cognitive Impairment

Introduction: Age-related functional decline elevates the risk of car accidents. Whether specific cognitive impairments and physical frailty increase the risk of car accidents is still unclarified. Objective: This study examines the association between car accidents, frailty, and cognitive function, owing to an increase in car accidents related to older adults. Methods: Data were collected from 12,013 older adults (45.4% women, mean age: 71.7 years [min: 60, max: 96]) enrolled in the National Center for Geriatrics and Gerontology (NCGG) – Study of Geriatric Syndromes. A 2-year self-reported history of car accidents was assessed. The Japanese cardiovascular health study index was used as the criterion and included the following components of frailty: shrinking, weakness, exhaustion, low activity, and slowness. “Frailty” was assigned a value of 1 or more based on these components. Cognitive function was assessed using the NCGG Functional Assessment Tool, and cognitive impairment was assessed using a standardized value. Results: Of the participants, 1,117 (9.3%) had a car accident history. The proportions of the frailty components’ applicability were observed in the car accidents group compared to the non-car accidents group: shrinking (p = 0.006), exhaustion (p = 0.031), low activity (p = 0.034), and slowness (p = 0.030), but not weakness (p = 0.452). The proportion of cognitive impairment in executive function was also higher in the car accidents group (p = 0.011). A logistic regression analysis showed that both frailty (OR 1.26, 95% CI 1.11–1.43; p < 0.001) and cognitive impairment (OR 1.26, 95% CI 1.11–1.43, p < 0.001) are associated with car accidents. Discussion: This study’s findings contribute to enhancing the utility of risk assessments for older drivers. Further study is required to clarify the risk of car accidents.