Characteristics of Older Adults Assessed at Risk of Dementia When Taking the Driver's License Test and Subsequently Visited Our Hospital Alone

Abstract

Purpose: In Japan, under the revised Road Traffic Law in 2017, adults aged ≥75 years must take a cognitive function assessment when renewing their driver’s licenses or after committing certain traffic violations. Individuals assessed to belong to Category 1 (“demented”) cannot renew their licenses without submitting a medical certificate to the Public Safety Commission. This study aimed to clarify their characteristics and expand knowledge about driving license renewal in “demented” older adults.

Methods: The study included 56 older adults judged to be “demented” on cognitive function assessment. They visited the outpatient clinic of the Department of Neuropsychiatry, St. Marianna University Hospital, during a 5-year period from March 2017 to March 2022. Their medical information, such as social background factors and diagnoses, were extracted retrospectively from medical records and analyzed using t-tests, chi-square tests, and Fisher's exact tests where appropriate.

Results: No participants were diagnosed as having “no dementia” in the medical reports submitted to the Public Safety Commission (which also includes a “mild cognitive impairment” category). Most participants were men (n=52); 75% had been married, 85% had children, and 78% lived with someone. Those who visited the clinic alone were significantly more likely to discontinue visits after diagnosis (p=0.019) and were often unmarried or divorced (p<0.01). All accompanied patients were married. No significant link was found between cohabitation status and visit type.

Discussion: Lack of association between visit type and cohabitation status suggests a preference for visiting the clinic alone, even when not physically isolated. Over 70% were married, had children, and lived with someone. Most participants were men, reflecting older men's low help-seeking tendencies and preference for limited social ties. When evaluating license renewal, it is important to consider both physical and psychological isolation. The latter may be influenced by older adults' tendencies to withhold personal information that might affect how others perceive and trust them.