Physicians, elderly drivers, and dementia

In western countries, the proportion of drivers who are elderly is increasing rapidly; over a quarter of the driving population will be 55 years of age or older by the year 2000. Although elderly drivers tend to drive less and may avoid night driving, the number of car accidents and the severity of injuries sustained in such accidents by distance driven increases strikingly after the age of 65. But how can doctors identify those elderly drivers who are a danger to themselves and others? And, once they are identified, how should clinicians balance the effects of removing a driving licence, which may greatly affect a patient’s lifestyle, against public safety and breach of confidentiality if the patient refuses to give up his or her licence voluntarily? Medical decisions about illnesses that predispose to loss of consciousness are fairly clear-cut, but normal ageing processes and dementia can be much

difficult to identify and to assess; moreover, there seems little correlation between tests of mental performance and driving ability. Comparisons between practices in different countries may provide some answers, but the introduction of modified driving tests for elderly drivers with some evidence of mild impairment but who wish to retain their driving licence should be considered. more

elderly are also more likely to die in car accidents;6if pedestrians are included, motor accidents in the elderly are the second most common cause for their admission to US emergency rooms7 and of accidental death. Although some commentators have suggested that the absolute risk of elderly drivers remains small,4,8 they tend to overlook the expected increase in the number of elderly drivers and the fact that crude accident statistics do not take into account modified driving practices such as reduced mileage and avoidance of night driving.9 It should also be remembered that whereas most societies legislate against two of the most important factors in road accidents-speeding and alcohol (both associated with a third, inexperienced youth),10 the scrutiny of risk factors associated with motor crashes in the elderly is less intense. Is it desirable or feasible to identify those elderly people most at risk of driving accidents?

The human factor Human error is the most important cause of car accidents -3 and is the main factor (whether or not judgment is impaired for other reasons) in up to 71 % of crashes. How does ageing affect the likelihood of driver error? Traffic offences might give some clues: drivers over 70 years of age tend to be convicted of sign, right-of-way, and turning offences rather than speeding, faulty equipment, and serious law violations." Reduced dynamic visual acuity and reaction time, and difficulties with divided attention tasks,12 deficits in later life that may contribute reduced safety on the roads. Moreover, elderly people tend not to recognise age-related deficits in sensory abilities that are relevant to driving.,13 and to underestimate driving dangers while overestimating their own driving skills. But although normal age-related changes can undeniably impair driving ability, age-related diseases might be a more important cause of motor accidents among the elderly. Dementia is a particular worry: it is common and may affect 10% of those aged over 65 and 20% of people over 85 years of age;14 most of those affected live in the community. A patient with dementia may have limited insight, early diagnosis is often difficult, and many cases are unknown to family practitioners.15 The cognitive and perceptual deficits of dementia include memory loss, reduced attention span, difficulties in visual perception, disordered scan-paths, impaired visuospatial discrimination, and reduction in visual fields;16,17 all of these factors may interfere with driving skills.

are among functional


of motor transport did not foresee that would become such a universal and accessible skill. driving Indeed one of them, Carl Benz, thought that the market for motor cars would be limited because no more than a million people would be trainable as chauffeurs. The rising proportion of elderly people who drive would also have surprised him. Point-prevalence figures of about 14.4 million drivers over 65 years of age in the USA in 1983, and nearly 3 million over the age of 60 in the UK in 1990, conceal this trend. Longitudinal data from the USA illustrate the startling growth in the proportion of elderly drivers in western countries: only 5-9% of drivers were over 60 in 1940, but this proportion has risen to 7-4% in 1952, and to 11 -4% by 1960.1 If present trends continue, over a quarter of the driving population by the year 2000 and well over a third by 2050 will be people aged over 55 years.2 This demographic change in driver age is important because the number of crashes and the severity of injuries by distance driven rise alarmingly after the age of 65, and come to resemble those for 15-25-year-old people.s The The


ADDRESS: Department of Care of the Elderly, Hospital, Bristol BS16 1LE, UK (D O’Neill, MRCPI).



Not surprisingly, continued driving in elderly people with dementia is the subject of increasing concern. Even in the 1960s a study of drivers in a retirement community showed a significantly increased risk of accidents in those afflicted by "senility" (presumably dementia),18 and 31 % of drivers who were assessed were classed as "senile". A 1988 report9 on driving practices in the elderly noted that cognitive function seemed to have little influence on whether elderly drivers stopped driving. Friedland and colleaguesl9 showed that patients with Alzheimer-type dementia were nearly five times more likely to have a car accident than were healthy age-matched controls. Nearly half the patients with dementia had had at least one crash before they stopped driving. Errors at crossroads, traffic signals, or while changing lanes accounted for most accidents.19 LucasBlaustein et al2° found that almost a third of a sample of patients with dementia reported a crash since onset of the illness and nearly half those who continued to drive got lost regularly. In the UK, many patients with dementia continue to drive despite a striking deterioration in driving performance.21 Indeed, a deterioration of driving skills was one of the first signs of dementing illness in about 10% of patients, yet withdrawal from driving was usually initiated by a family member or a physician rather than the

patient.21 An Mo T for man?

Many European countries such as Germany, Sweden, and Austria routinely test vehicles as they age, but do not test elderly drivers. In the UK, vehicles are checked annually after 3 years (the ’MoT’), but driving licence renewal after the age of 70 depends on a self-declaration of health (or illness): if disabilities are not reported they may not be detected because some (such as dementia) may not be known to the family doctor, 22 and most general practitioners do not ask many of their elderly patients about driving habits.23 Striking under-declaration of conditions are well known in self-reporting systems. The reporting of suspected medical unfitness to drive also raises important ethical issues about confidentiality. Most professional associations for physicians accept that the principle of confidentiality is partly or wholly countered by a "common good" principle for the protection of third parties if direct advice to the patient is ignored.24 In the UK, this conflict of interest is recognised by a compromise in which the physician only informs the licensing authority directly if he or she has failed to persuade the patient to inform the authority and had not been able to involve relatives in the decision.24,2S By contrast, 8 states in the USA require physicians to report to the local licensing authority all patients whose medical conditions might affect their ability to driver In Canada, reporting of suspected medical unfitness to drive is mandatory in 4 provinces but greater discretion is accorded to the physician in the other 4.2’ Most patients with dementia who are reported to licensing authorities will almost certainly lose their driving licences. But it should also be remembered that the use of a car is of great importance to elderly people: in one UK study, 77% of elderly drivers rated their car as essential or very important to their way of life.28 Driving is probably both a right and a privilege: but 42% of the elderly think that driving is a right as opposed to 27% who think that it is a privilege.28 Compulsory removal of a driving licence represents a potential breach of civil rights.26 If we are to protect our patients as well as the public, we need to know

whether we can predict which factors in dementia predict loss of driving capability and to be reassured that licensing authorities will not remove a driving licence without reasonable cause.

Fitness to drive The assessment of medical fitness to drive in age-related illnesses may be very difficult. Although many countries have quite clear-cut protocols for illnesses which predispose to syncope or loss of consciousness,25’z9 the premises on which they were based may have been weakened by larger community studies .30 Guidelines for less circumscribed and more heterogeneous neurodegenerative conditions such as dementia, subtypes of which may present with only modest cognitive loss and very slow progression, are even less certain, and were highlighted by a report2l in which almost a third of drivers with dementia had no evidence of impaired driving skills. Patients in whom there is clear-cut evidence of loss of driving skills or of gross behavioural or psychological dysfunction are easy to identify, but for the many subjects without gross deficit a decision about fitness to drive may be difficult to make on medical assessment alone. Selfdeclaration forms, as proposed for Parkinson’s disease,31 are inappropriate in dementia and the usefulness of psychometric testing is uncertain. A correlation between psychometric screening tests and driving ability has been described among elderly drivers of varied cognitive status,32 but no such correlation has been found among drivers with Alzheimer’s disease19 and dementia.21 Activity of daily living scales provide an index of practical function and may be a more useful guide;21 other tests, such as traffic sign recognition, merit further evaluation.33 Accounts from relatives of changes in a patient’s driving skill may be helpful, and an occupational therapy evaluation might help to form an impression of the patient’s overall abilities.34 In the absence of a clear clinical indicator, direct assessment of driving ability rather than a diagnostic label or an isolated mental test score should be the guide for continued driving in dementia.35 Cheap simulators based on personal computers are unlikely to represent a realistic alternative to test driving-as a normal test drive or an assessment of low speed, off-road driving tasks,36 preferably near the patient’s home and incorporating various levels of difficulty. Such tests could provide the basis for a graded approach to licensing, such as restricting driving to daytime or journeys below a certain distance, as occurs in New Zealand ’29 rather than the stark choice of unrestricted driving or no driving, as in most countries. Most elderly drivers without dementia accept that their doctor’s advice is very influential in making a decision to give up driving,28 and many patients with dementia will eventually respond to pressure from their families or physician.21 When it is necessary to send a medical report to a licensing authority without a patient’s consent, it would be extremely helpful for the physician to know that further assessment, as some form of driving test, would be arranged before a final decision was made. Confidence that driving licensing authorities had sensitive and realistic policies which favoured assessment of driving skills rather than diagnostic labels would greatly reduce doctors’ worries about possible breaches of confidentiality. It must also not be forgotten that removal of their driving licence may be insufficient for the small minority of patients who are resistant to persuasion, oblivious to the removal of their licence, and unfit to drive: their vehicle may need to be disabled.37


Discussion Should there be regular screening for age-related diseases driving ability among elderly drivers? This question may be difficult to answer because the presence of any form of screening might influence patients and families to give up driving without going through the screening process. Cross-national comparisons are needed between the selfreport system in the UK; the requirement of a certificate of health from the family doctor at an arbitrary age threshold and at each subsequent renewal in the Republic of Ireland, Switzerland, Denmark, and Greece; and regular retesting (with an increased frequency of testing after 69 years) in some US states. New Zealand combines elements of the last two approaches by requiring regular medical testing of people over 70 years and a driving test at two-yearly intervals after the age of 76.29 The routine use of psychometric tests alone to assess driving skills would probably be ineffective,38 and the lack of guidelines on clinical markers of driving performance in mild to moderate dementia should promote caution in attempting any purely medical assessment of fitness to drive in this population. Closer liaison between the medical profession and licensing authorities is urgently needed to promote further research and understanding of this topic. The effects of any opportunistic approach with mandatory reporting of drivers with dementia could perhaps be reviewed by comparison of licence suspensions before and after implementation of the law.39 Whatever the outcome of such comparisons, changing an established system may be difficult: a survey of British drivers showed strong resistance to the concept of regular medical checks to retain driving licences.28



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1990; 46: 63-76. 24. General Medical Council. Professional conduct and discipline: fitness to practice. London: GMC, 1985: 19-21. 25. Raffle A, ed. Medical aspects of fitness to drive. London: HM Stationery Office, 1985: 92-93. 26. Reuben DB, Stillman RA, Traines M. The aging driver: medicine, policy and ethics. J Am Geriatr Soc 1988; 36: 1135-42. 27. Coopersmith HG, Korner-Bitensky NA, Mayo NE. Determining

medical fitness to drive: physicians’ responsibilities in Canada. Can Med Assoc J 1989; 140: 375-78. 28. Automobile Association Foundation for Road Safety Research. Motoring and the older driver. Basingstoke, Hants: AA, 1988: 40. 29. New Zealand Ministry of Transport. Medical aspects of fitness to drive. Wellington, New Zealand: Ministry of Transport, 1990. 30. Hansotia P, Broste SK. The effect of epilepsy or diabetes mellitus on the risk of automobile accidents. N Engl J Med 1991; 324: 22-26. 31. Editorial. Driving and Parkinson’s disease. Lancet 1990; 336: 781. 32. Odenheimer GL. Cognitive dysfunction and driving ability. J Am Geriatr Soc 1991; 39: A9. 33. Carr D, Madden D, Cohen HJ, Jackson TW. The use of traffic identification signs to identify drivers with dementia. J Am Geriatr Soc 1991; 39: A62. 34. Taira ED, ed.. Assessing the driving ability of the elderly. Binghampton, New York: Haworth Press, 1989. 35. Drachmann DA. Who may drive? Who may not? Who shall decide? Ann Neurol 1988; 24: 787-88. 36. Betts T. The value of low speed, off-road driving tasks. Int Clin Psychopharmacol 1988; 3 (suppl 1): 88-98. 37. Donnelly RE, Karlinsky H. The impact of Alzheimer’s disease on driving ability: a review. J Geriatr Psychiatry Neurol 1990; 3: 67-72. 38. Seib H. Erkenntnisse der Unfallursachenforschung zur altersbedingten Leistungsminderung der älteren Verkehrsteilnehmer, ihr Unfallsrisiko und die rechtichen Konsequentzen. Z Gerontol 1990; 23: 86-96. 39. Williams C, Odenheimer G. Why elderly drivers lose their licences. J Am Geriatr Soc 1991; 39: A72.

From The Lancet Medical statistics? The Council of the Statistical Society has, we understand, appointed a "Committee of Hospital Statistics", to consider the best means of collecting facts that will be susceptible of numerical analysis on an uniform plan, in periodical returns made from the various sanatory institutions of the country. Something of this kind has long been wanted, and its utility universally felt. Physicians and surgeons perceive that, in addition to the handicraft part of physic, there is, as in other departments of philosophy, a wide field for scientific generalisation, founded upon systematic observation.... We wish this project, as well as every other calculated to improve medical science, success; and we have the satisfaction of believing that The Lancet has prepared the way for it, as well as for other useful inquiries in hospitals, whose doors were formerly closed against inquiry of every kind. Such a proposal as has been referred to above would have startled many of the big-wigged and gold-caned gentlemen of the "good old school" out of their propriety, and have been regarded as the sure indication of some deep-laid conspiracy against their peace or reputation-some contrivance for surreptitiously seizing the secrets of their pharmacy, or for exposing the quackery of their pretensions. Treasurers and jobbing governors would have been in arms. This is much altered now. We should not be surprised if the Committee of the Statistical Society obtained, instead of opposition, the active and intelligent co-operation of all the most enlightened men connected with our (Jan 1, 1842) public institutions.

Physicians, elderly drivers, and dementia.

In western countries, the proportion of drivers who are elderly is increasing rapidly; over a quarter of the driving population will be 55 years of ag...
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