The fatal crash rate tends to increase when drivers turn 65 – but there are few validated tools available for predicting when an individual driver’s risk may start to increase. A new study from researchers at the University of Washington School of Public Health and School of Medicine, published in the Journal of the American Geriatrics Society, explored whether cognitive test scores can be linked to higher crash risk.

The study, which analyzed data on 2,615 licensed Washington drivers over age 65, found a small correlation between crash risk and lower scores on a test known as the Cognitive Abilities Screening Instrument using item response theory, or CASI-IRT. The test measures skills such as attention, concentration, short-term memory, visual construction and judgment, all key tasks for driving safely.

The findings suggest that CASI-IRT may be useful to evaluate crash risk, but authors noted that more research is needed to help guide older drivers, their families and their physicians in making the decision whether to continue driving.

“Social, logistical, and health factors must be considered as older individuals, families, clinicians, and other stakeholders seek to balance the independence of driving with the safety of older drivers and those with whom they share the road,” said lead author Laura Fraade-Blanar, a recent graduate of the UW School of Public Health and current postdoctoral fellow at the RAND Corporation.