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A new guideline by the American Academy of Neurology (AAN) helps neurologists determine when people with Alzheimer's disease and other dementias should stop driving. (The AAN develops “clinical practice guidelines” to help neurologists make decisions about the prevention, diagnosis, treatment, and prognosis of neurologic disorders. Each guideline makes specific recommendations based upon a rigorous and comprehensive evaluation of all available scientific evidence.) It's an update of the AAN's 2000 guideline, which concluded that “patients with mild dementia categorically should not drive,” says Donald J. Iverson, M.D., lead guideline author and a neurologist with the Humboldt Neurological Medical Group, Inc., in Eureka, CA. “The update softens the message to ‘should strongly consider discontinuing driving,’” Dr. Iverson explains. The guideline is published in the April 20, 2010 issue of Neurology (and a summary of it for patients and caregivers is available at aan.com/guidelines ; search for “driving and dementia”).
Clinical trial evidence illustrates that patients' driving skills deteriorate with increasing dementia severity, according to the guideline. Yet studies also show that as many as 76 percent of dementia patients pass an on-road driving test, making a recommendation that patients with dementia absolutely should not drive under any conditions too restrictive, says Dr. Iverson: “[The guideline authors] wanted to preserve the patient's autonomy to some extent. Giving up driving is associated with depression and increased awareness of mortality. We wanted to limit that as much as possible.”
Guideline authors reviewed 422 out of 6,000 studies published between 1970 and 2006. Among their recommendations, the authors recommend physicians use the five-point Clinical Dementia Rating (CDR) scale to identify those dementia patients who are at an increased risk for unsafe driving. The CDR scale—which detects cognitive and functional impairments—is based on a physician's examination of the patient as well as information from caregivers.
Indeed, caregiver concerns about the driving ability of a person with dementia are a useful part of the evaluation process, the guideline authors note. For example, they found that a caregiver's rating of the patient's driving as “marginal” or “unsafe” is probably useful, whereas a patient's self-rating of “safe” is not.
What behaviors may indicate an increased risk for unsafe driving? Guideline authors identified these, among others: a decrease in the number of miles driven; the avoidance of driving in certain situations, such as at night or in the rain; a recent history of collisions or moving violations; and aggressive or impulsive personality traits.
Dr. Iverson compares stopping driving to “the same end-of-life issue as financial conservatorship, transition to assisted living, or advanced health directives.” The decision to stop driving, he says, should be made after the clinician, patient, and caregivers or family discuss it openly. In addition, state laws may be considered, because some states require doctors to report any medical conditions that may impact driving ability.
The guideline also suggests follow-up evaluations every six months may be useful to determine whether driving risk has increased.
These behaviors are signs that a person with dementia may be an unsafe driver:
▸ Decrease in number of miles driven
▸ Avoidance of driving in certain situations, such as at night or in the rain
▸ Recent history of collisions or moving violations
▸ Aggressive or impulsive personality traits