Laws requiring doctors to report a dementia diagnosis to the DMV may backfire

Some states require that physicians report a diagnosis of dementia, including Alzheimer’s disease, to the DMV. A new study suggests these mandates may have unintended consequences.

Published April 25 in the Journal of the American Medical Association’s JAMA Network Open, the study was led by researchers at the USC Dornsife College of Letters, Arts and Sciences in collaboration with a Harvard University researcher.

Why it matters: The increasing number of elderly drivers presents significant safety concerns for policymakers, physicians and society, considering they’re at greater risk of dementia. But no studies have examined the effects of state policies that require clinicians to report dementia cases to the DMV — until now.

• Previous studies that explored the connection between cognitive decline and road safety found contradictory evidence regarding dementia’s link to accidents.
• One potential explanation for this is that researchers hadn’t factored in DMV reporting requirements.

At issue: For the new study, the researchers sought to determine whether physicians who are mandated by the DMV to report a diagnosis of dementia will be less likely to establish such a diagnosis. The short answer seems to be “yes.”

• The study is the first to provide evidence for potential negative consequences of laws that mandate physicians report dementia diagnoses to the DMV.

Key finding:  Physicians in states with mandatory reporting laws are 50% more likely to underdiagnose dementia, compared to physicians in states without such mandates.

The Big Picture: In the United States, the number of drivers aged 65 and older has increased by 22% since 2012, totaling nearly 56 million in 2021.

• About 7 million Americans in this age group currently suffer from dementia. That number is expected to increase to nearly 12 million by 2040.

Important: If patients withhold symptoms out of fear their doctor will report a dementia diagnosis to the DMV,or physicians are reluctant to examine dementia symptoms for fear their patient could lose their driving license, that would worsen health outcomes and increase health care costs.

• “In light of our findings, lawmakers need to weigh the potential downside of mandating that physicians report dementia diagnoses to the DMV,” said Soeren Mattke, professor (research) of economics and director of the Brain Health Observatory at the USC Dornsife Center for Economic and Social Research(CESR).

What else? Knowing that their physicians must report a dementia diagnosis to the DMV, patients might be more inclined to refuse further assessments.

• The loss of a driver’s license adds to the stigma associated with dementia.
• Studies also suggest that older adults without a driver’s license engage in fewer out-of-home activities and have a higher risk of depression.

In her words: “Patients already resist revealing symptoms of cognitive decline. Facing the threat of losing their driving privileges could make them less likely to seek essential cognitive evaluation, leading to more overlooked or postponed diagnoses,” said Ying Liu, a research scientist at CESR and co-author of the study.

In dispute: There is scant evidence that mandatory reporting laws reduce accident risks. States enact mandatory reporting laws believing they can enhance driving safety.

• The researchers looked for studies on the association between mandatory reporting policies and accidents from 2000 to 2023 and found only one. That study found no significant difference in dementia rates among older drivers hospitalized after accidents in states with physician-reporting laws compared to other states.
• Studies using driving simulators show that cognitive impairment correlates with decreased perception, visual attention and reaction time. Whether these changes increase the risk of accidents remains unclear.

The lack of evidence hinders researchers’ ability to determine whether the benefits of reporting mandates outweigh the risks associated with the increase in missed diagnoses.

• Mattke suggests that people with cognitive decline may voluntarily change their behavior, such as driving less or avoiding driving at night, to mitigate the risk of accidents.

Zoom in: The diverse range of state policies regarding the mandatory reporting of dementia reflects the complexity and varying interpretations of the evidence.

• Four states — California, Delaware, Oregon and Pennsylvania — mandate under threat of legal consequences that physicians report diagnoses of dementia to their DMVs.
• New Jersey and Nevada require clinicians to report medical conditions that could pose a potential threat to road safety, though they do not explicitly mention Alzheimer’s disease or cognitive impairment.
• Fourteen states ask drivers to self-report dementia diagnoses, which typically triggers a medical examination or driving test.
• The remaining 32 states and the District of Columbia have no mandates but allow physicians — as well as family members and police officers — to report dementia diagnoses. (Maryland, New Mexico and Texas accept reports )

Study methods: The researchers, analyzing Medicare data used for a previous study on mild cognitive impairment diagnoses, classified states based on their reporting laws.

• The team sorted more than 223,000 primary care clinicians into three groups: mandated clinician reporting; mandated self-reporting; and no explicit requirements.
• They then analyzed the relationship between these categories and the likelihood of primary care clinicians underdiagnosing dementia among their patients.

What’s next? Mattke and his team say future study is needed to better understand the unintended consequences and risk-benefit tradeoffs of these policies.