Office‐Based Evaluation of the Older Driver (2006)

Driving places demands on attention, memory, problem solving, and information processing—cognitive skills that often decline with aging. The number and proportion of older people who drive has increased dramatically during the past decades, and this trend is expected to continue. Indeed, the proportion of persons aged 65 and older who will be driving is expected to double between now and 2020.1 By 2020, it is estimated that there will be 38 million drivers aged 70 and older on the road in the United States, compared with 13 million today. Older-driver involvement in fatal crashes is projected to increase 155% by 2030, accounting for 54% of the total projected increase in fatal crashes for all drivers.2 As this important demographic group grows and continues to delay driving cessation, the burden of injurious motor vehicle crashes will weigh more heavily on the public health and older drivers in particular. Declining driver competence is a public health problem, and it is a challenge for health professionals to recognize impaired driving ability in older people. Of equal concern is that driving is key to independent function and quality of life. Access to friends, families, employment, shopping and commerce, personal care, social interaction, educational and cultural enrichment, and religious expression—nearly all the benefits of modern society—depends on the ability to transport oneself from one location to another. High levels of mobility mean high levels of access, choice, and opportunity that can lead to self-fulfillment and enrichment, whereas low levels of mobility can lead to isolation and cultural impoverishment. The responsibility for determining the driving fitness of older adults is increasingly falling upon the medical profession. Measures determining when a person should restrict or cease driving would permit timely institution of countermeasures (including medical interventions) to assist older adults to continue driving as late in life as possible, as long as they can do so safely. Predictive measures would also allow time for planning alternative mechanisms to meet mobility needs and promote continued independent living if medical intervention is not available. The article by Molnar et al.3 in the current issue of the Journal of the American Geriatrics Society, examines the utility of office-based cognition screening tests to determine fitness to drive in patients with dementia. At the outset, the reader should be reminded that screening tests for fitness to drive are just that, screening tests. They should be used to assist in the process of determining further evaluation, referrals for additional evaluation, and referring patients for formal driver evaluation. This is the recommendation in the American Medical Association's Physician's Guide to Assessing and Counseling the Older Driver.4 For clinicians without access to formal driver-evaluation services, the screening tests may help them make a referral to the medical review board of their state's Department of Motor Vehicles. In either case, at least in the United States, the medical review board makes the final determination; the physician does not revoke the driver's license. Molnar and colleagues'3 selection of studies to be reviewed required that participants have dementia or Alzheimer's disease according to accepted diagnostic criterion for these conditions. This is an important element for the reader's consideration. Many studies that have examined predictors of unsafe driving have used well-known, validated neuropsychological tests (e.g., Mini-Mental State Examination, Trails B) but have not required Diagnostic and Statistical Manual of Mental Disorders or National Institute of Neurological and Communicative Disorders and Stroke—Alzheimer's Disease and Related Disorders Association diagnostic criteria and were excluded from the review. Given that dementia affects some 3 to 4 million people in North America alone and that clinicians encounter them frequently, a review article focused solely on driving predictors in the dementia population is not too restrictive. Unfortunately, cognitive impairment, as well as issues related to driving ability, is often overlooked in the context of a brief office visit. Cognitive impairment and dementia are surprisingly prevalent in apparently healthy older individuals, affecting up to one third of people aged 65 and older, yet it remains undiagnosed in 25% to 90%.5-8 Clinicians faced with evaluating a patient for driving fitness should review those studies that identified potential driving predictors for patients who may not yet meet the criteria for dementia, because their cognitive impairment may be sufficient to cause unsafe driving. The screening tests shown to be associated with driving performance in these studies may provide guidance in the examination and subsequent referral process. It is also important to consider that decline in driving skills and the rate of decline is highly variable; in some studies, a substantial minority of cognitively impaired individuals demonstrated driving competence that was judged to be normal,9-12 and such competence was maintained over a 2-year period.9 This suggests high individual variability in the rate of decline in driving skills in individuals with cognitive impairment and dementia. In some parts of the country, driving privileges are revoked based solely on the diagnosis of dementia or on the prescription of medication for dementia.13 This approach derives from uncertainty about the progression of cognitive decline and about which driving errors are associated with specific cognitive deficiencies. This is significant in that report of a crash (an outcome variable for many studies), by the patient, proxy report, or Department of Motor Vehicles record, may not provide information about the crash (e.g., fault, circumstances leading to or surrounding the crash), and a causal relationship cannot automatically be assumed. Observation of specific errors during actual driving, through on-road testing or simulator testing, provides more-objective data. Driving is a complex task requiring a range of cognitive and psychomotor abilities including memory, judgment, motor control, decision-making and attention, and executive function. No single short cognition test captures all these domains to a degree such that clinicians would be comfortable making absolute recommendations about a person's driving involvement. What Molnar and colleagues have brought to our attention is that, for those front-line clinicians who are looking for specific cutpoints, scoring algorithms, and decision rules, the driving and dementia literature falls short. Although many brief cognition screening tests have been associated with driving outcomes (crash, on-road, and simulator performance), the “how to” instructions are not self-evident. The literature may fall short on this, but one must consider the tremendous body of knowledge that this research has developed and countless numbers of patients and families who have benefited because clinicians are talking with them about driving. Financial Disclosure: I am declaring no conflict of interest. Author Contributions: I am responsible for the entire contents of this editorial. Sponsor's Role: None.