NEW YORK, Jun 26 (Reuters Health) - Patients with early Alzheimer's disease
are at an increased risk of accidents when they drive. The finding has prompted
the American Academy of Neurology to issue guidelines to doctors to help them
determine which Alzheimer's patients can continue to drive, and when patients
should stop driving.
US researchers estimate that the risk of traffic accidents caused by
patients with Alzheimer's is about the same as that for those in the 16- to
21-year-old age group or those who drive after drinking with blood alcohol
levels under the legal limit.
"Driving is often necessary for people to remain independent in our society,
but accidents are a major cause of injury and death," said Dr. Richard M.
Dubinsky of Kansas University Medical Center in Kansas City, who helped to frame
the new guidelines. "The American Academy of Neurology developed these
guidelines to help answer the question--Does driving by people with Alzheimer's
pose a significant traffic safety problem?"
Dubinsky and colleagues evaluated 14 research studies looking at Alzheimer's
patients and driving. Some of these recorded accident rates, some used simulated
performance tests, and some studied how well Alzheimer's patients with slight
cognitive impairment process visual information while driving.
"Almost all of (the crash rate) studies demonstrate an increased crash rate
for drivers with Alzheimer's disease," the authors write in the June issue of
Neurology. They note that this rate increased over time in individuals tested
because by the nature of the disease, cognitive impairment in Alzheimer's
patients increases over time.
Dubinsky and colleagues developed the guidelines for the academy based on
their review of study findings. The guidelines differentiate levels of cognitive
impairment. Slight cognitive impairment is characterized by mild forgetfulness
that does not interfere with everyday activities, some difficulty with problem
solving, and slight difficulties with hobbies and tasks at home, but patients at
this level are capable of handling their personal care needs, like hygiene and
getting dressed. On a standard measure of dementia called the Clinical Dementia
Rating scale (CDR), these patients would score 0.5.
The guidelines state that patients with this level of impairment "pose a
significant traffic safety problem when compared to other elder drivers," and
should have their driving performance carefully evaluated. In addition, these
patients should be reassessed for driving every 6 months, because they are
likely to progress to more severe dementia.
"Patients with Alzheimer's disease with a severity of CDR 1 or greater (that
is, more than slight impairment) have a substantially increased accident rate
and driving performance errors, and therefore should not drive an automobile,"
the group recommends.
Dubinsky and colleagues also point out that more research is needed in this
area. "It may be possible that if there are typical accidents due to dementia,
that driving limitations or technologic solutions could allow drivers to
decrease their crash risk," they note, calling for research to evaluate
"reliable predictors of future unsafe driving, the efficacy of frequent driving
performance assessment in demented drivers, and the effects of driver retraining
programs."
In a statement, Dubinsky also noted that, "Any recommendation by healthcare
providers about driving by people with Alzheimer's disease must comply with
state laws and be made in conjunction with evaluation of the individual patient
and with the input of their caregiver."
