People in early stages of dementia may not have excellent driving skills, but it is not certain that they actually have a higher accident rate. Previous studies pointed out that drivers with dementia performed more poorly on driving tests than others their age. However, the studies did not consistently find that this translated into a higher accident rate. Of three studies that used state records to determine crash rates, only one found that drivers with dementia had a higher accident risk. The findings highlighted the difficulty of determining whether or not people with dementia should stop driving. Some people believe that, for the sake of safety, people should have their driver's licenses revoked after a diagnosis of dementia. But several international medical groups have taken a stand that a diagnosis of dementia, by itself, should not automatically preclude people from driving. There is a general consensus that people who are moderately or seriously impaired should not drive. But people with mild dementia should have their driving ability tested on an individual basis. To substantiate this, researchers at the Ottawa Health Research Institute and Ottawa Hospital in Ontario reviewed 23 people to study the relationship between dementia, driving performance and crash risk. Of 16 studies that measured driving skills—usually through road tests or driving simulators—all showed that drivers with dementia performed more poorly than other drivers. On the other hand, the studies that evaluated crash rates yielded inconsistent results. One reason for this discrepancy could be the fact that many drivers with dementia restrict their driving, which lowers their chances to have an accident. The findings suggested that people with dementia might have a higher risk of accidents. Given the risks, those with mild impairment should have their driving ability regularly tested, every six to 12 months. Dementia patients should also understand, from the time they are diagnosed, that they will eventually have to give up driving. If patients and their families plan for this inevitability, it can make the transition easier for everyone.
Journal of the American Geriatrics Society ,
June 2007