No driving for Miss Daisy

In that article, Dr. Hing is quoted as saying that: The problem is that there’s no scientific standard for making the call. Some doctors are too strict and others, too lenient. “That kind of variation in practice is rather unfair. … It puts a huge strain on the physician-patient relationship.” [p. 3822]

Cognitive impairment is one of the conditions where the variability and guesswork referred to by Dr.Hing may be most likely with the unfortunate consequences he mentions. Many patients, especially geriatric patients, have multiple medical conditions and medications that can contribute to cognitive impairment. These complexities place physicians in a difficult position if they are to rely on clinical judgments about fitness to drive. A better approach is to evaluate the effects of co-morbidities, polypharmacy, age, and other factors by evaluating combined impairment through a relevant functional assessment of driving competence. This approach is consistent with the one recommended by the Canadian Medical Association.

In British Columbia, the Office of the Superintendent of Motor Vehicles (OSMV) is the office of the Provincial Government that issues and removes licenses. They depend on physicians to identify those individuals that have a medical condition impacting their ability to drive a car safely. These conditions and the evaluation processes are clearly laid out in the new guidelines for Determination of Medical Fitness to Drive issued by the OSMV in July 2010 and approved by the British Columbia Medical Association. Amongst the conditions listed is cognitive impairment.

The BC OSMV Guidelines specify two lines of approach with regards to cognitive impairment in patients:

i. If a physician makes a diagnosis of Dementia in an individual where minimally that person’s executive functioning (2 or more instrumental Activities of Daily Living) is impacted, their driver’s license can be cancelled.

ii. If a physician has a suspicion that there is cognitive impairment, he may perform a SIMARD-MD test and refer for testing by DriveABLE according to their SIMARD-MD score. A failing score on the SIMARD-MD prompts reporting to the OSMV. The OSMV then makes the final decision on whether to cancel the driver’s license.

We have had the ability in BC to refer to DriveABLE for years. In my practice, I find it very useful in cases where patients are in the mild dementia category and driving may or may not have declined to an unsafe level". I also find it helpful for patients who are having great difficulty in accepting that their days of driving are over because it allows me to discuss external scientifically based evidence that they are no longer safe to drive."

One of the major challenges for physicians in discussing driving assessments is the ‘user-pay’ approach. Having the DriveABLE assessment paid for by the government in BC has removed that barrier.

I do not think that we have yet reached a steady state for assessment of driving capacity in cases of cognitive impairment. Dr. Hing’s research, or the research of others, may lead to more effective tools sometime in the future. For now, I do know that I am responsible for making the best possible decisions for my patients. The approach outlined in the 2010 Guidelines of the BC OSMV helps me to do that.

Thank you

Conflict of Interest:

None declared