Driving with Dementia

As the US population ages, especially the demographic bulge we call the Boomers, there are more and more older drivers. Anyone who has driven behind an oldster knows there’s a concern about road safety as the elders, and I include myself, continue to drive. While the AMA has guidelines outlining physician responsibility in reporting medically impaired drivers, e.g., epilepsy, cognitive impairment reporting remains a grey area.

That greyness extends to State policies on reporting dementia; only four states require reporting [1], 14 recommend it, and the remaining 32 are silent. Another ambiguity is hard data on whether cognitive impairment results in more accidents. Simulators and common sense “suggest cognitive impairment correlates with reduced hazard perception, visual attention, and reaction time.” However, the effect on accidents is mixed. Finally, there is an intrinsic conflict between my autonomous decision to drive and a societal decision to protect the public.

The current study, published in JAMA Network Open, investigates the influence of State law on clinicians’ likelihood of diagnosing dementia. The data on the actual number of cases of dementia came from Medicare. Information on State law came from “the reporting guidelines in the state’s legislation, the state DMV website, and relevant educational and patient care websites.”

“Every physician and surgeon shall report immediately to the local health officer in writing, the name, date of birth, and address of every patient at least 14 years of age or older whom the physician and surgeon has diagnosed as having a case of a disorder characterized by lapses of consciousness. … and shall include Alzheimer’s disease and those related disorders that are severe enough to be likely to impair a person’s ability to operate a motor vehicle in the definition.”

- California State Law

Four states, including California, mandated clinician reporting. “Self-reporting” States had legislation or “a DMV website indicating that individuals were expected to disclose medical conditions that affected driving abilities.” [emphasis added]. The remaining states had no explicit requirements, introducing the more nuanced word choice, may.

The study looked at the diagnoses made by primary care physicians in these three different reporting environments. The primary care practices were similar in size and demographics with the usual “disparities.” The study makes two initial assumptions: that the prevalence of dementia is evenly distributed across states and that physicians obey the law. Anyone trying to get an opioid for pain relief after surgery knows just how law-abiding physicians are; the even distribution of demented is in part corrected for by a model used by the researchers to predict how many cases of dementia should be present in a given state. While validated and published, that model has an accuracy of about 80%, leaving some wiggle room in interpreting the research findings.

• Primary care clinicians in states with clinician reporting mandates had an adjusted 12.4% probability of underdiagnosing dementia, 59% higher than the other two groups: 7.8% for clinicians in states with driver self-reporting laws and 7.7% in states without mandates.
• Clinicians in small towns (Odds Ratio, 1.36) or rural areas (Odds Ratio, 1.65) had higher odds of underdiagnosing dementia compared to those in metropolitan areas.
• Clinicians specializing in geriatrics had the lowest odds of underdiagnosing compared to other specialties.

Why would physicians mandated to report dementia to the State be 50% more likely to underdiagnose dementia?

The first clue lies in the greater odds in small towns and rural areas. Restricting driving in these areas and, to a similar extent, in the suburbs can and frequently does lead to reduced out-of-home activities – you become homebound. And there is evidence that those restrictions lead to a greater risk of “depressive symptoms.” Safe, inexpensive public transportation in larger metropolitan areas may mitigate that real concern. Patients may be hesitant to disclose concerns or undergo testing when they fear that a dementia diagnosis will result in loss of mobility.

Physicians, too, are caught in a double bind; raising the issue of dementia with patients, especially in its earliest stages, is difficult – provoking anxiety in patients and physicians. It can significantly harm what is a critical relationship. In the states with mandatory reporting, there may be additional legal scrutiny for a failure to report.

The lack of definitive evidence that dementia inevitably leads to poorer driving, and yes, I know that common sense says that must be the case, provides enough uncertainty to quell some fears. As the researchers write about the underreporting

“With the lack of clear evidence for positive associations of clinician reporting mandates with road safety, it remains challenging to determine whether the benefits outweigh the risk that our study uncovered.”

The debate surrounding driving with dementia is multifaceted, encompassing medical, legal, and societal dimensions. While some states mandate reporting, others leave it to the discretion of individuals, creating a regulatory patchwork. The study's findings highlight that fear of legal repercussions may influence physicians' and patients' medical decision-making. Balancing the autonomy of individuals with the responsibility to ensure public safety remains a delicate equilibrium – simply mandating does not seem to be efficacious.

[1] California, Delaware, Oregon, and Pennsylvania. “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.”

Source: State Department of Motor Vehicles Reporting Mandates of Dementia Diagnoses and Dementia Underdiagnosis JAMA Network Open DOI: 10.1001/jamanetworkopen.2024.8889