“This was surprising, as we know that older drivers stop driving based on the advice of their physicians and, if reported to licensing authorities, few regain driving privileges,” said lead author Yll Agimi, Ph.D., M.P.H., M.S., a health data scientist at Salient CGRT Inc. who did the research while a doctoral student at Pitt Public Health. “Physicians are required to ensure the well-being of patients with dementia by also monitoring their driving competence. That leads us to conclude that other licensing requirements may act as the principal means of identifying at-risk older drivers, before physicians identify and report a patient with a medical impairment, such as dementia.”
Previous studies have shown that drivers with dementia perform significantly worse in on-road testing, compared to those without dementia. Prevalence of dementia increases with age, from 9 percent among adults ages 65 and older, to 30 percent among those over 85.
At the time of the study, three states – Pennsylvania, Oregon and California – required physicians to report drivers with dementia to licensing authorities. Twenty-seven states provided legal protection to physicians who report their patients, regardless of whether such reporting is required by law.
Only five states do not require that drivers present in-person – which is thought to allow licensing personnel to assess driving fitness – for license renewal at least once within two or three renewal cycles. Two states require road testing at licensing renewal, and 36 states require vision testing.
Agimi and his colleagues analyzed the crash-related hospital admissions from the states reporting data between 2004 and 2009. Among 136,987 hospitalized older drivers, 5,564 had a diagnosis of dementia.
Hospitalized drivers aged 60 to 69 in states with in-person renewal laws were 37 to 38 percent less likely to have dementia than drivers in states without such laws and 23 to 28 percent less likely in states with vision testing at in-person renewal. However, physician reporting laws were not associated with a lower likelihood of dementia among hospitalized drivers. These findings held even after the researchers accounted for other factors that could influence crash rates, ranging from police enforcement of safe driving to inclement weather.
“The results of our study point to age-based licensing requirements as an effective way to improve safety,” said co-author Steven M. Albert, Ph.D., M.S., chair and professor of the Department of Behavioral and Community Health Sciences at Pitt Public Health. “But such requirements also may cause social isolation and depression, and may be seen as ageist and discriminatory. So it is very important that our findings spur further study to determine the best approach to ensure safe driving for all on the road while avoiding a negative impact on the mental health of older adults.”
Additional authors of this study are Ada O. Youk, Ph.D., and Patricia Documet, M.D., Dr.P.H., of Pitt Public Health, and Claudia A. Steiner, M.D., M.P.H., Agency for Healthcare Research and Quality (AHRQ) at the time of study.
This work was supported by an Association of Schools and Programs of Public Health/National Highway Traffic Safety Administration fellowship awarded to Agimi, and data access obtained through collaboration with the Healthcare Cost and Utilization Project, AHRQ of the U.S. Department of Health and Human Services.