Car Accidents Associated with Physical Frailty and Cognitive Impairment

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.

This study examines the association between car accidents, frailty, and cognitive function, owing to an increase in car accidents related to older adults.

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.

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.

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.