Driving Safety & Older Adults: The Latest Research from the Journal of the American Geriatrics Society (JAGS)
Thursday, November 22, 2012
Two studies in the November 2012 issue of the Journal of the American Geriatrics Society evaluated driving in older adults. The first study looked at whether the driving setting affects performance in older adults with a range of cognitive function (their thinking, reasoning, understanding, and memory). The second study evaluated the situations in which older drivers with dementia become lost, how they are found, and the role of notification systems.
Why These Studies Were Done
As the number of older adults has increased, so too has the number of older drivers. According to the Federal Highway Administration, in 2009, there were 33 million licensed drivers aged 65 and older in the United States—a 23% increase from 1999. The National Highway Safety Administration reported that more than 5,500 older adults were killed and more than 183,000 were injured in motor vehicle crashes in 2008.
Twenty percent of people with dementia drive. There is a great deal of research on people with dementia who become lost while walking, including the situations under which this can happen and the results of people becoming lost. However, there is a lack of similar information about older drivers with dementia.
Older adults’ driving ability is a personal and public safety issue that many families are dealing with and that researchers are studying.
What They Found
In the first study, researchers from the Rhode Island Hospital and Brown University evaluated driving performance in 103 older adults between 60 and 90 years old who were either healthy (44) or had very mild or mild dementia (59). Each person was evaluated in a road test and by reviewing four hours of video recording that had been taken from cameras installed in their cars while driving in their natural driving settings. The goal of the study was to compare the ratings of a driver's abilities when tested in a road test versus when they were in their own environment.
The participants were evaluated by the rate of driving errors and global ratings of safety (passed with and without recommendations, marginal with restrictions, or failed). The assessments were made by a professional instructor who was not aware of the cognitive health of the subjects.
Overall, both groups ranked the same in performance and safety on both the road test and in their natural driving conditions. However, more driving errors were detected in the drivers’ own environment for both cognitively healthy and cognitively impaired participants. While cognitively impaired participants made more errors, the types of errors made by the cognitively impaired and healthy participants, such as not checking for blind spots or staying in their driving lane, were similar. The cognitively impaired participants’ history of crashes—when adjusted for miles driven—corresponded with the errors seen in road test results but not the errors seen in their own driving environments.
“The road test is a good indicator of driving abilities in older adults, but there are variables,” said Jennifer Davis, PhD, of the department of psychiatry and human behavior at the Rhode Island Hospital, who is the lead author of the study. “Some older adults perform better on the road test because the conditions are controlled, it requires a more limited set of skills, and the instructor is guiding them. Thus, they may pass the road test but not do well driving in familiar settings. So while the road test is considered a reasonable indicator of how older drivers will fare in their own environments, it doesn’t tell the whole story. More study is needed to determine the overall fitness of older drivers with and without cognitive impairment.”
In the second study, researchers from the University of South Florida, Tampa, and the New York University Langone School of Medicine, looked at 156 law enforcement records of drivers who had a Silver Alert issued in Florida during the period of October 2008 through May 2010. Silver Alerts are issued in Florida for missing drivers who had dementia.
The study showed that the average age of missing drivers was approximately 80. More than 70% were male and nearly 80% were Caucasian. Those for whom a Silver Alert notification was issued were more likely to be found by law enforcement compared to good Samaritans responding to citizen alerts. They were also more likely to be involved in a driving error such as speeding, wrong turns, and accidents and to have traveled farther distances.
The researchers determined that half of the drivers became lost while engaging in normal activities, such as driving to doctor’s appointments, visiting friends, dining out, and shopping. Caregivers were aware and approved of the activities. Ten got lost when there was a new element to their routine such as an extra stop, different directions, an unplanned trip, or when they became agitated.
“We learned that there are different characteristics for people with dementia who become lost while driving compared to those who become lost while walking,” said Meredeth A. Rowe, PhD, of the College of Nursing at the University of South Florida, who led the study. “Drivers wandered farther away from their last location and tended to end up at businesses and roadways and were located by law enforcement. This knowledge could help communities develop effective ways to prevent an incident, organize a search plan, and use citizen alerts. Our ultimate goal is to better predict which people with dementia are likeliest to get lost while driving, the situations in which this occurs, and how to develop effective plans for safe recovery.”
What You Can Do
Discussing when older relatives should give up driving is one of the most difficult things family members must do. Many older adults feel that taking away their ability to drive is taking away their independence. Yet, at a certain point, it becomes critical both for their safety and the safety of the public.
People with cognitive impairment face special circumstances, so regular consultations with neurologists, geriatricians, geriatric psychiatrists, and other clinicians are important.
Periodically ride in the car with an older driver to observe their reaction time, whether they are following the rules of the road, and whether they have safe judgment. If you have any concerns, get the help of physicians, social workers, friends, and other trusted advisors to develop a plan to keep your loved one safe.
This summary is from the full reports that appear in the November 2012 issue of the Journal of the American Geriatrics Society (JAGS):
Road Test and Naturalistic Driving Performance in Healthy and Cognitively Impaired Older Adults: Does Environment Matter? Authored by Jennifer D. Davis, PhD, George D. Papandonatos, PhD, Lindsay A. Miller, BA, Scott D. Hewitt, MA, Elena K. Festa, PhD, William C. Heindel, PhD, and Brian R. Ott, MD.
Missing Drivers with Dementia: Antecedents and Recovery. Authored by Meredith A. Rowe, PhD, Catherine A. Greenblum, PhD, Marie Boltz, PhD, and James E. Galvin, MD, MPH.