Older drivers will account for a larger number and percentage of the driving population in the future. Despite typically driving fewer miles than younger drivers, older drivers have the second highest rate of motor vehicle crashes per mile driven, exceeded only by drivers younger than 24 years. Older drivers also tend to have more serious outcomes from motor vehicle crashes than younger drivers. Two recent articles in Canadian Family Physician, one by Hogan and the other by Molnar and colleagues, address the family physician’s role in assessing the older patient’s ability to drive.
Both articles stress that multiple factors can contribute to impaired driving, including medication use, chronic diseases, changes associated with aging, and a combination of these factors. To help physicians identify patients at risk of driving impairment, the American Medical Association has identified “red flags” (http://www.ama-assn.org/go/olderdrivers) that include recent acute illnesses, chronic conditions, the use of certain classes of medications, and the presence of specific symptoms. Molnar and colleagues use this list and data from other sources to propose two acronyms for use in practice—the SAFE DRIVE checklist and the CanDRIVE assessment algorithm. Although not strictly evidence-based, these tools are thought to be appropriate for use in practice. Both articles also provide guidance on eliciting an appropriate driving history from older patients, using questionnaires and toolkits of key questions to ask patients and family members. These cover the patient’s perception of his or her driving ability; criticism of the patient’s driving by others; stress or symptoms caused by or associated with driving; physical symptoms that affect driving ability; and increased difficulty in driving, such as close calls, problems with parking, or getting lost.
The evaluation of the older driver must be individualized and should include assessment of physical and cognitive functions. Experts disagree about the most suitable test of cognitive abilities related to driving. The Mini-Mental State Examination is used widely to assess general cognitive function and screen for dementia, but it does not address visual perception, selective attention, judgment, insight, and the use of alcohol or medications.
The Clinical Dementia Rating (CDR) scale provides a score ranging from zero (no dementia) to 3 (severe dementia). It takes about 40 minutes to complete and addresses six domains, although not all of them are associated with driving. The 1994 International Consensus Conference on Dementia and Driving concluded that physicians should recommend that patients stop driving if they score a 2 or 3 on the CDR. The American Academy of Neurology recommends that patients with Alzheimer’s disease should not drive if they have a CDR score of 1, and that even patients with possible Alzheimer’s disease who score 0.5 on the CDR pose a serious risk and should undergo performance evaluation.
Specialized testing includes occupational therapy assessment and neuropsychological evaluation, but road testing remains the most widely accepted criterion for driving safety. Road testing is expensive, and its availability may be limited. The use of driving simulators has not yet been developed for widespread clinical testing of older drivers.
Both articles emphasize that physicians must be aware of national standards and state and local regulations governing safe driving by older patients. Nevertheless, assisting patients and families with this important decision requires considerable skill in patient assessment and negotiation to implement the necessary changes. Although several tools exist to assist in identifying the “at-risk” older driver and in clarifying the type and severity of the risk, most guidelines are not based on scientific evidence, and significant controversy persists.
editor's note: This topic appears to be gaining more recognition, with recent articles1 providing welcome guidance for office assessment of older drivers. Nevertheless, this is an extremely challenging area for family physicians. As the articles illustrate, the topic is complex: every assessment must be individualized and multifaceted, and the available tools and guidelines remain untested or unreliable (despite recent improvements). As family physicians, however, we are aware of so much more than just the professional assessment of driving competency. A related editorial2 mentions the difficulties faced by older patients living in rural areas if driving is restricted or prohibited, but these problems also affect older patients in other areas. Public transportation systems can be inadequate or inappropriate, making a simple trip to the store an overwhelming and stressful experience for older patients. Any change in driving must be accompanied by a referral to the local agency on aging to discuss transportation options, and physicians must discuss transportation options with the patient’s family. Even more seriously, cessation or curtailment of driving is a significant risk factor for other problems. It often seems to mark the beginning of significant declines in function and always poses the risk of depression. Even the most robust patient experiences the sense of loss and of growing encroachment of dependency on his or her daily activities. A wise family physician takes a moment to acknowledge these feelings, validate the decision to cease driving, and remind the patient that he or she has a physician who recognizes the challenges of successful aging and is prepared to help.— A.D.W.