Soon, tests that may predict Alzheimer's patient's driving safety

Doctors may soon be able to use certain cognitive tests to help judge which patients with Alzheimer's disease can drive without endangering themselves or others, according to a new study led by a University of Iowa biostatistician.

Doctors may soon be able to use certain cognitive tests to help judge which patients with Alzheimer's disease can drive without endangering themselves or others, according to a new study led by a University of Iowa biostatistician.

"The number of people with dementia is increasing as our population ages, and we will face a growing public health problem of elderly drivers with memory loss," said the study's author, Jeffrey Dawson, associate professor of biostatistics in the University of Iowa College of Public Health.

In the study, 40 drivers with early Alzheimer's disease and 115 elderly drivers without this diagnosis underwent a combination of off-road tests that measured thinking, movement and visual skills.

The participants also drove a 35-mile route in and outside a city. Driving safety errors were recorded by a driving expert, based on a video review of the drive.

The researchers found that drivers with Alzheimer's disease committed an average of 42 safety mistakes, or 27 percent more errors than those made by the drivers without Alzheimer''s disease, who committed an average of 33 safety errors on the test drive.

The most common mistakes were lane violations. For every five years older the participant was, the number of safety errors went up by about two and a half, whether or not the driver had Alzheimer''s disease.

Among the study drivers with Alzheimer's disease, those who performed better on the off-road tests also made fewer on-road safety errors.

"The goal is to prevent crashes while still maximizing patient's rights and freedom to be mobile," Dawson said.

"By measuring driver performance through off-road tests of memory and visual and motor abilities, we may be able to develop a standardized assessment of a person's fitness to drive," Dawson added.

The research was published in the Feb. 10 print issue of Neurology, the medical journal of the American Academy of Neurology.