Dementia and Driving: A Compatible Combination?
A conversation about driving with dementia exploded in the press in recent weeks. Everyone is weighing in on this debate, with potential stakes running obviously high. Certainly the decision to take away a patient’s licence could never be undertaken lightly, so how can a physician accurately determine driving risks associated with dementia?
A patient’s score on the Mini-Mental Status Examination (MMSE) score, when considered on its own, is a surprisingly poor predictor of a driver’s ability to drive safely. In fact, studies have shown that as many as 76% of patients with mild dementia are still able to pass an on-road driving test. Last month, in a strong effort to refine the entire process of assessing driving risk associated with dementia, the American Academy of Neurology issued updated guidelines for physicians. These updated practice parameters take into account the following characteristics that have proven useful for identifying patients at increased risk for unsafe driving:
• Clinical Dementia Rating Scale (CDR);
• A caregiver’s rating of a patient’s driving ability as ‘marginal’ or ‘unsafe’;
• The patient’s driving history, including accidents and citations;
• Self-reported ‘situational avoidance’ [Studies have shown that self-restricted driving, perhaps by avoidance of highway driving or night driving, or driving in inclement weather, or simply reduced overall mileage, is an accurate indicator of a driver at increased risk];
• An MMSE score of 24 or less; and
• Aggressive or impulsive personality characteristics.
This multi-faceted risk assessment brings the Americans more in line with the current Canadian approach, as outlined in the Canadian Medical Association’s document: Determining Medical Fitness to Operate Motor Vehicles CMA Driver’s Guide which takes this stance: "The driving ability of people with mild dementia should be tested on an individual basis. Studies have shown that a significant percentage of those in the early stages of dementia are able to operate a motor vehicle safely."
Jennifer Hartman, guest blogger
