Can Cognitive Screening for License Renewal Reduce Collisions in Older Drivers?

A change in policy that required cognitive screening for older drivers resulted in a decrease in motor vehicle collisions but an increase in pedestrian or cyclist injury. These were the findings of a study published in the Journal of the American Geriatrics Society.

Some evidence suggests that older individuals may be more dangerous drivers. As such, Denmark, Japan, and Taiwan, among others, require older individuals to undergo cognitive screening for license renewal. Despite these testing requirements, there has been little evidence that cognitive screening decreases motor vehicle collisions.

For the study, researchers evaluated national, time-series data prior to and after a policy change in March 2017 requiring cognitive screening among drivers aged 70 years and older in Japan. Police-reported data on motor vehicle collisions among drivers and road injuries among pedestrians and cyclists were evaluated between 2012 and 2019.

During the study period in Japan, the number of licensed drivers aged 70 years and older increased from 8.0 to 11.9 million. During this time there were 602,995 motor vehicle collisions and 196,889 road injuries among pedestrians and cyclists involving individuals aged 70 years and older.

In general, more motor vehicle collisions involved men (72%) and more road injuries involved women (59%).

Among men aged 75-79, 80-84, and 85 years and older, prior to the cognitive testing policy, the change in the monthly rate ratio (RR) for motor vehicle collisions was increasing (RR range, 4.5 x 10^-4-8.4 x 10^-5) whereas after the policy, the rate was decreasing (RR range, -9.6 x 10^-4 to -1.8 x 10^-3). Among women, the rate was increasing prior to the policy (RR range, 1.3 x 10^-3-2.7 x 10^-4) but did not differ from zero after the policy.

For road injuries, men aged 75-79, 80-84, and 85 years and older had an increasing trend prior to the policy (RR range, 1.5 x 10^-3-3.9 x 10^-3) and a trend that did not differ from zero after the policy change. Women had an increasing trend both prior to (RR range, 1.9 x 10^-3-2.7 x 10^-3) and after (RR range, 1.2 x 10^-3-8.7 x 10^-4) the policy change.

These trends indicated that after the policy change, 3252 fewer men and 418 fewer women drivers aged 75 years and older had a motor vehicle collision whereas 154 more men and 805 more women aged 75 years and older had a pedestrian or cycling road injury.

The sensitivity analysis that used only at-fault data found similar trends.

These findings may not be applicable for near-future driving, as newer vehicles come with additional technologies designed to prevent user errors, such as automatic emergency brakes or self-driving programs.

These data supported the use of cognitive screening for driver’s license renewal, as motor vehicle collisions decreased among drivers aged 75 years and older after a policy change, the researchers acknowledged. However, the policy change also increased road injuries for the same population as pedestrians or cyclists.

“Cognitively screening older drivers at license renewal and promoting voluntary surrender of licenses may prevent motor vehicle collisions,” the researchers wrote. However, this is associated with a concurrent increase in road injuries among older pedestrians and cyclists. They concluded that “Future studies should examine the effectiveness of mitigation measures, such as alternative, safe transportation, and accommodations for pedestrians and cyclists.”