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Risk assessment in older drivers is affected not only by our underst<strong>and</strong>ing <strong>of</strong> models <strong>of</strong> drivingbehaviour. <strong>and</strong> empirical studies <strong>of</strong> disease <strong>and</strong> crash risk, but also by clinical attributes common tothe assessment <strong>of</strong> function in older patients. Inter-individual variability is extremely important <strong>and</strong>necessitates a case by case approach.Factors relating to age-related diseases include not only adifferent spectrum <strong>of</strong> illness to younger people, but also the presence <strong>of</strong> multiple illnesses. In anyone patient, is it the arthritis, the dementia, the visual acuity or even the multiple medications whichis affecting driving? Within the rubric <strong>of</strong> one iilness there may be multiple facets. For example, thereis an increased risk <strong>of</strong> crashes with Parkinson's disease's. ". The illness may involve problems <strong>of</strong>motor function, depression <strong>and</strong> impaired cognitive function. Rather than stating Parkinson's disease isdangerous for driving, it is vital to take a phenomenological approach. The depression <strong>and</strong> the motorfunction must be treated <strong>and</strong> cognitive function assessed <strong>and</strong> managed before any decisions aremade about fitness to drive.Any broader assessment <strong>of</strong> group risk due to illness will require careful scrutiny <strong>of</strong> the relevantliterature. The source <strong>of</strong> information is critical to decision-making. Did it come from a specialisedclinic or from the community? Was it a large study? What level <strong>of</strong> risk is implied for our patients? Astudy on diabetes, epilepsy <strong>and</strong> risk <strong>of</strong> crashes is a useful illustration <strong>of</strong> this". Epilepsy <strong>and</strong> diabetesare both illnesses that have been very clearly defined in many fitness-to-drive manuals, <strong>of</strong>ten withstringent licence restrictions <strong>and</strong>/or punitive insurance loadings. This large-scale community studydemonstrated that the increased risks were in fact quite small. It is probably no coincidence that theUnited Kingdom Driver <strong>and</strong> Vehicle licencing Authority has sub?equently relaxed the restrictions onboth diabetes <strong>and</strong> epilepsy". If a more selected group is studied, for example people over 65 in ahealth maintenance organisation, the relative risk for diabetes <strong>and</strong> crashes may be higher'''. As in anyapplication <strong>of</strong> the medical literature, the physician has to relate the sample population to his ownpractice.The Insurance Corporation <strong>of</strong> British Columbia's gives a wider driving population-based perspective <strong>of</strong>risk <strong>of</strong> driving <strong>and</strong> dementia'·, but many studies <strong>of</strong> driving <strong>and</strong> illness have originated fromspecialised clinics in cardiology, dementia or syncope. Studies <strong>of</strong> dementia <strong>and</strong> driving which aretaken retrospectively from dementia clinics tend to show a high risk, whereas those which are quasiprospective<strong>and</strong> which look at the early stages <strong>of</strong> dementia show a less pronounced pattern <strong>of</strong> risk.In the first two years <strong>of</strong> dementia the risk approximates to that <strong>of</strong> the general population". This is animportant finding because many physicians assume that dementia is an absolute contra - indicationto driving. In a UK study <strong>of</strong> dementia deterioration in driving skills was a phenomenon <strong>of</strong> the earlystage in 10% <strong>of</strong> the patients studied". A higher than expected number <strong>of</strong> tangles <strong>and</strong> plaques have65 Dubinsky, R.M., Gray, C, Husted, D., Busenbark, K., Vetere-Overfield, B., Wiltfong, D. et al. 'Driving in Parkinson'sdisease'. Neurology 1991; 41 (4):517-20.66 Lings, S., Dupont, E. 'Driving with Parkinson's disease. A controlled laboratory investigation'. Acta Neurol Sc<strong>and</strong>1992;86 (1):33-9,67 Hansotia, P., Broste, S.K. 'The effect <strong>of</strong> epilepsy or diabetes mellitus on the risk <strong>of</strong> automobile accidents' N Engl J Med1991;324 (1):22-6.68 Medical Advisory Branch D. 'At a glance guide to the current medical st<strong>and</strong>ards <strong>of</strong> fitness to drive'. 1994 (November).69 Koepsell, T.D., Wolf, M.E., McCloskey, L, Buchner, D.M., Louie, D., Wagner, E.H., et al. 'Medical conditions <strong>and</strong> motorvehicle collision injuries in older adults'. J Amer Ger/atr Sac 1994;42: 695-700.70 Cooper, P.J., Tallman, K., Tuokko, H., Lynn Beattie, B. 'Vehicle crash involvement <strong>and</strong> cognitive deficit in older drivers'.Journal <strong>of</strong> Safety Research 1993; 24(1):9-17. .71 Drachman, D.A., Swearer, J.M. 'Driving <strong>and</strong> Alzheimer's disease: the risk <strong>of</strong> crashes' [published erratum appears inNeurology 1994 Jan;44(1):4). Neurology 1993;43(12):2448-56.72 O'Neill, D., Neubauer, K" Boyle, M" Gerrard, J., Surmon, D., Wilcock, G.K., 'Dementia <strong>and</strong> driving'. J R Sac Med 1992;85 (4):199-202.<strong>Assessment</strong> <strong>of</strong> <strong>Older</strong> <strong>People's</strong> <strong>Health</strong> <strong>and</strong> <strong>Social</strong> <strong>Care</strong> <strong>Needs</strong> <strong>and</strong> Preferences