When should patients with Alzheimer disease stop driving?
Deniz Erten-Lyons, MD
Patients with Alzheimer disease (AD) usually have problems withmemory. During their illness, they may also start having problemswith making good decisions. They may begin having difficultywith interpreting things that they see and may react slower.They may have trouble following directions and may get lost.These abilities are all necessary for safe driving. Therefore,all patients with AD will have to stop driving at some pointduring their illness. Patients with advanced AD should not bedriving at all. However, it is often not clear when a personwith mild symptoms of AD should stop driving.
In this issue of Neurology®, a study by Dr. Ott and coauthors1examined driving skills in patients with early AD. The studygoal was to understand the changes in driving skills over timein patients with AD. They wanted to find out when a person withAD starts having trouble that could interfere with safe driving.They also wanted to understand what other factors might leadto worsening driving skills in patients with AD.
The authors followed 84 patients with very mild and mild AD.A rating scale called the Clinical Dementia Rating Scale wasused to determine whether a patient had very mild or mild AD.The researchers did not include patients with more advanceddementia. Patients had on-road driving tests every 6 months.Patients would "fail," meaning they were not safe drivers anymore,if one of three things happened: (1) if the patient could notpass the on-road driving test; (2) if the patient had an at-faultcar accident; and (3) if the patient's dementia became worsethan mild.
The authors also included 45 elderly people who did not haveAD. This group served as a comparison group. This group hadan on-road driving test when they entered the study. About halfalso had retesting at 18 months. The authors did not includepeople with other conditions that could affect driving skills.Examples of such conditions are amputations or vision problems.
Results of the first on-road driving test.
Overall, the majority of patients with very mild or mild ADwere able to pass the first on-road driving test. All researchparticipants without AD passed. More patients with mild AD failedcompared to those with very mild AD.
Results of follow-up.
All participants showed a decline in driving skills. Patientswith mild AD showed the fastest decline. Patients with mildAD became unsafe drivers after an average of 11 months. Patientswith very mild AD remained safe drivers for an average of 1.7years.
What else was associated with unsafe driving?
AD patients who were over 76 years old or had less than 14 yearsof education were more likely to be unsafe drivers.
Comparison of crashes.
Drivers with dementia had fewer car crashes than drivers inthe healthy elderly comparison group. This difference was explainedby the fact that many dementia patients reduced or stopped theirdriving during the course of the study.
According to some current guidelines, patients with even mildAD should stop driving.2 However, in the current study, mostpatients with mild AD were able to pass the on-road drivingtest. They remained safe drivers for several months. This studyalso suggests that among patients with AD, those who are olderand have less education are more likely to become unsafe driversfaster.
Patients with AD will have to stop driving at some point duringtheir illness. In the early stages, an individual's drivingability should ideally be tested by an on-road driving test.Driving skills should be reassessed at least every 6 months.Families and caregivers need to observe for any warning signsthat may indicate unsafe driving. Patients who have more advanceddementia (moderate to severe) should not be driving at all.
On-road driving tests are expensive and not available everywhere.Further research is needed to come up with tests that providerscan use in the office to determine whether a patient is ableto drive safely. Also, it is not clear how well on-road drivingtests actually show how an individual drives in real traffic.Future research is needed to help us understand this better.
Alzheimer disease (AD) is the most common cause of dementiain the United States.
In AD, clusters of proteins accumulate in the brain. These leadto destruction and loss of brain cells. The changes in the brainstart many years before a person actually shows symptoms.
The earliest symptom usually is loss of recent memory or troublecoming up with words. Other symptoms include misplacing things,not being able to do familiar tasks, confusion about dates,not recognizing places or people, change in mood or behavior,and losing interest in doing things.
As a result of changes in the brain caused by the disease, aperson with AD may exhibit problems with reacting fast, makingdecisions, perception, multi-tasking, and memory. All of thesecan result in impaired driving.
WHAT ARE SOME OF THE WARNING SIGNS THAT A PATIENT WITH AD IS STARTING TO HAVE TROUBLE DRIVING?
The following are some warning signs indicating that a patientwith AD may be having trouble with driving3:
Not remembering the location of familiar places, having a hardtime with new directions
Not observing traffic signs
Mistakingthe gas pedal for the brake
Not driving at appropriate speeds
Stopping inappropriately (for example, at a green light)
Becomingconfused and overwhelmed while driving (for example,findingtraffic signals confusing)
Making poor or slow decisions whiledriving
Having difficulty making left turns
Noticing thatother drivers frequently honk
Dents and scrapes on the car
Becoming angry and frustrated when driving
Drifting outof one's lane
Not looking when moving from one lane to another
Taking much longer to get to places
Family and friends should ride frequently with the AD patientin order to look for any of the warning signs that the patientmay be starting to have trouble with driving.
WHAT ARE SOME WAYS TO HELP A PATIENT WITH AD GIVE UP DRIVING?
Since all patients with AD will have to stop driving at somepoint, it is important to start talking about this early on.Reducing one's driving gradually over time works better formost patients. For example, a patient with early AD can startdriving only during the day, or can start avoiding highways,or can drive only in familiar places and short distances.
It is important to try to help a person stay independent afterhe or she gives up driving. Family and friends can be a bighelp. They can provide rides to the patient. They can also helpin planning other forms of transportation. Some other optionsto get to places are using taxis, shuttles, or public transportation.Information on transportation for the elderly may be obtainedfrom the local Agency on Aging and the National Transit Hotline.
WHAT IF THE PATIENT WITH AD REFUSES TO STOP DRIVING?
Sometimes patients with AD may not be aware of the problemsthey are having. In these cases they may refuse to stop driving.It may be helpful to have the health care provider, in additionto the family members, discuss driving. It may also help toget a prescription saying "do not drive" from the doctor. Ifthese measures fail, caregivers may control access to the car.Ways to do this include hiding the car keys, disabling the car,or parking the car elsewhere. If these fail, caregivers mayrequest that the Department of Motor Vehicles (DMV) performa driving test on the person with AD.3
WHERE CAN A PATIENT WITH AD GET ON-ROAD DRIVING TESTING DONE?
While some state agencies (such as the local DMV) may providedriving tests, you may also obtain fee-for-service assessments.A list of therapists who provide such assessments may be obtainedfrom your local Alzheimer's Disease Association chapter or theAmerican Occupational Therapy Association.
Ott BR, Heindel WC, Papandonatos GD, et al A longitudinal study of drivers with Alzheimer disease. Neurology 2008;70:1171–1178.[Abstract/Free Full Text]
Dubinsky RM, Stein AC, Lyons K. Practice parameter: risk of driving and Alzheimer's disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2000;54:2205–2211.[Abstract/Free Full Text]
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