Section 14: The Aging Driver
14.4 Dementia (continued)
It is generally well accepted that dementia patients who drive, as a group, pose substantial safety problems. However, clear cut guidelines for the identification and evaluation of individual at-risk drivers are lacking. In some reports, the investigators have argued that as soon as a diagnosis of dementia is made, a recommendation be given not to drive (Friedland et al., 1988; Lucas-Blaustein et al., 1988). Others, however, have argued that diagnosis alone is insufficient for revocation of a driver's license (Drachman, 1988; Drachman and Swearer, 1993; Fitten et al., 1995). One of the problems with using diagnosis is that severity does not correlate sufficiently with driving performance to be a valid criterion for determining driving cessation (Johannson et al., 1997). According to Drachman (1988) "the limitation of the privilege to drive should be based on demonstration of impaired driving competence rather than a stigmatizing label, such as AD" (p. 787). This is a strong argument given the fact that, although many drivers with dementia as a group do have high crash rates, a significant minority of patients with early dementia show no evidence of deterioration of driving skills. Importantly, recent empirical evidence suggests that almost one third of drivers with a dementing illness are competent to drive in the early stages of their illness (Dobbs et al., 1997, Fitten et al., 1995; O'Neill, 1992). In light of this evidence, restrictions in driving or de-licensing based on a medical diagnosis of dementia alone not only unfairly penalizes the patient, it can limit their independence and mobility in the early stages of the disease when they may still be competent to drive.
Table 36 Guidelines for the Aging Driver (Reproduced with permission)
Advanced age is not in itself a barrier to driving. Therefore, in assessing an older person’s ability to drive safely, it is important to consider his or her functional ability, rather than chronological age. |
Although the rate of physical and mental decline varies greatly from person to person, the physiologic changes that accompany aging eventually affect everyone's driving ability. The borderline is often hazy between a hazardous deterioration and a decline that can be compensated for by long experience and voluntary limitation of driving.
Many drivers, as they grow older, find it increasingly difficult to cope with the power and speed of the modern automobile and the progressively increasing traffic congestion on both urban and rural roads. Keeping in step with the traffic on high-speed freeways requires the utmost concentration. |
Adequate cognitive functioning is important to the driving task Ability to carry out the following processes should be gauged in assessing driving competence:
1. Attention.
2. Concentration.
3. Thought processing.
4. Problem solving skills.
5. Memory. |
Slowed reaction time, lack or attentiveness, poor judgment, and faulty attitudes are responsible for many crashes at all ages.
These factors assume an increasing importance with advancing years.
An older driver who is physically fit may be quite unable to drive safely on today’s crowded streets because of mental deterioration. |
Frequently an older driver has several minor physical defects, each of which taken separately may not affect driving ability very much. However, when taken together these defects may make driving potentially dangerous, particularly if the defects are accompanied by some slowing of ability to convert perception and judgment into timely action. |
An older person often has several minor physical defects, each of which if taken separately may not affect driving ability very much, but when taken together may be dangerous.
The hazards increase if these physical defects are accompanied by some slowing of the ability to convert perception and judgment into timely action. |
Intellectual Impairment
Should not drive. The DLA will require a test by a driving assessor before considering issue of a license or conditional license. |
With documented dementia, the operation of any motor vehicle is risky. Individuals identified with possible dementia must have an assessment of their cognitive function.
Individuals scoring less than 24 on the Mini-Mental State Examination (MMSE) are ineligible to hold a driver’s license of any class pending complete neurological assessment.
Individuals suspected of showing poor judgment, poor reasoning ability, poor abstract thinking, and poor insight also should be evaluated for driving ability even if they have a MMSE score of 24 or higher. |
DLA = Driver Licensing Authority
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