Mild Alzheimer's Patients Can Drive Safely
Jan. 4, 2000 (Washington) -- A controversial new study shows that elderly
patients with a mild form of Alzheimer's disease are just as safe on the road
as their unimpaired counterparts, at least by one crucial measure. The study
compared the crash rates of 63 patients suffering from dementia of the
Alzheimer's type (DAT) with those of 58 healthy drivers, looking back at state
driving records over a five-year period.
"We found no difference in crash rates between drivers with DAT and
controls," write David Carr, MD, and his colleagues from the division of
geriatrics and gerontology at Washington University in St. Louis, in an article
appearing in the January issue of the Journal of the American Geriatrics
The surprising research comes in the wake of other findings that document a
doubling in the rate of DAT every five years in those older than 65 and a
tendency for patients with DAT to drive dangerously. "We know that some of
these people are safe drivers, at least at this stage," study co-author
John Morris, MD, tells WebMD. Morris, director of the memory and aging project
at Washington University, emphasizes that these patients are at the very
earliest stage of DAT, and their symptoms may be barely detectable.
"We want to allow people to maintain their driving independence as long
as they're safe but have them stop just before they demonstrate that they are
unsafe," says Morris. For example, he says that mildly impaired patients
should be evaluated every six months to see if their driving skills have
deteriorated. One predictor might be the ability to execute a left-turn safely.
According to Morris, a loss of driving privilege can lead to isolation and a
quicker decline in these patients.
In fact, while there were relatively few crashes in the study overall, the
accident rate was slightly higher (0.07 per year) for the non-demented group
than for those with DAT (0.06 per year for patients with the mild form and 0.04
per year for patients with very mild disease). Even though the results are not
statistically significant and those with mild DAT didn't drive as much as the
others in the study, the researchers say the data show a trend.
"[T]his finding is further evidence not to suspend driving privileges
based on diagnosis alone," write the authors. Contrary to the views of some
experts, the study indicates that having mild or very mild Alzheimer's disease
doesn't predict a decline in driving ability, at least for the first couple of
The patients were from the Alzheimer's Disease Research Center. Participants
of this registry are enrolled in studies of healthy aging and dementia and
return each year for an evaluation.