Mr. D, age 75, presents to your office with a 5-year history of gradually declining memory. His wife reports he is having difficulty with word finding, managing his finances, and shopping, and he needs supervision when using the stove. Nonetheless, he enjoys playing golf and drives himself to the golf course 3 times a week. He is compliant with his chronic medical therapy for hypertension, hypercholesterolemia, and asthma.
Patients with dementia who continue to drive pose a potential danger on the road, worry their families, and present challenges to clinicians. Most people would agree that patients with moderate or severe dementia should not drive, but a careful evaluation is required to assess whether a patient such as Mr. D with mild dementia remains fit to drive.
This article explores how dementia exacerbates age-related changes in driving ability and discusses how to assess driving in patients with dementia. Our goal is to help clinicians sort through data from in-office physical and cognitive assessments, family caregivers/informants’ reports, and (when available) on-road testing. We also discuss:
- guidelines for assessing older drivers that can help balance patients’ need for autonomy with public safety
- strategies for discussing driving cessation with patients and their families.
Driving: A privilege, not a right
Driving is central to older adults’ autonomy, and >75% of persons age ≥75 rely on driving as their primary mode of transportation.1 Driving cessation in this population has been associated with a 3-fold decrease in out-of-home activity2 and a 2.5-fold increase in depressive symptoms.3 Nonetheless, some 4.5 million Americans have Alzheimer’s disease (AD),4 and dementia poses a substantial risk to safe driving.
Although driving must be sacrificed when personal and public safety is at risk, most physicians perceive an uncomfortable conflict of interest between patient confidentiality and public safety.5 Assessing driving safety of patients with dementia can undermine the doctor-patient relationship and pose hardships for patients.
Mr. D has a 5-year history of memory problems that affect his daily functioning, yet he continues to drive. A longitudinal study of persons with dementia found that among the 29% who were driving at baseline, more than one-half were still behind the wheel 2 years later.6
Age and driving safety. Even in the absence of dementia, driving ability declines with aging (Tables 1 and 2).7,8 Older persons may self-regulate and restrict their driving to shorter distances, with fewer trips at night, on high-speed roads, or in unfamiliar situations. Their driving is rarely aggressive and they are unlikely to speed, but they may drive more slowly than other traffic.7,8 Although the overall rate of motor vehicle collisions declines with age:
- the rate of collisions per mile driven increases after age 659
- drivers age >65 have the highest fatality rate per mile driven among adults age ≥25.10
A dementia diagnosis is not sufficient to withdraw driving privileges, according to American Medical Association (AMA)/National Highway Traffic Safety Administration (NHTSA) guidelines. These recommend that you base decisions on the individual’s driving ability, and—when you have concerns—factor in a focused medical assessment and formal assessment of driving skills.10
Table 1
Age-related changes that may affect driving fitness
| Decreased physical capabilities, including declining muscle tone, flexibility, and reaction time |
| Decreased hearing and visual acuity |
| Increased fragility, resulting in longer time to heal should injuries occur |
| Increased medication use with possible side effect of drowsiness |
| Source: References 7,8 |
Table 2
Older drivers’ common traffic violations leading to crashes*
| Failure to obey traffic signals, including stop signs and red lights |
| Unsafe left turns (driver may inaccurately judge speed of oncoming vehicle) |
| Inappropriate turns (such as difficulty judging distance from oncoming cars, wide or narrow turns, or not timing the turn correctly with traffic lights) |
| Unsafe passing |
| Failure to yield |
| * These errors often lead to multivehicle accidents Source: References 7,8 |
CASE CONTINUED: Cognitive deficits quantified
You perform a Mini-Mental State Examination (MMSE). Mr. D scores 24/30, losing 1 point for orientation, 2 points for attention, 2 points for recall, and 1 point for copying. This score, along with his history, indicates mild dementia, although he claims he is a safe driver. On further cognitive testing, Mr. D completes the Trails A test in 90 seconds and Trails B test in 250 seconds (well below 1.5 standard deviations of the norm for his age and education).11 On the clock-drawing task, he drew a poorly organized clock, with unequal spaces between numbers and hands pointing to “10” and “11” instead of properly indicating “10 after 11.”