Driving and dementia in Ontario: a quantitative assessment of the problem.

Background: The population is becoming increasingly aged, and concomitantly, the prevalence of dementia is steadily rising. Persons aged 65 years and over are likely to continue driving for many years and often well into the dementia process.

Methods: Ontario Ministry of Transportation driving data, census data, and dementia prevalence data were combined to determine the number of persons with potential dementia who are driving, both now and in about 25 years' time.

Results: Actual and projected Ontario figures show that the number of senior drivers will increase markedly from just under 500,000 in 1986 to nearly 2,500,000 in 2028. Similarly, the number of drivers with dementia is also increasing. Although not all drivers with dementia are necessarily dangerous, most are estimated to continue driving well into the disease process. By combining the above-mentioned data sets, a best estimate of the number of drivers with dementia in Ontario was derived. It is estimated that this group has grown from just under 15,000 in 1986 to about 34,000 in 2000 and will number nearly 100,000 in 2028.

Interpretation: Increasingly, the responsibility for identifying drivers with dementia has fallen on the health care system, a role for which it was never designed nor equipped to handle. The risks associated with the dramatically increasing number of drivers with dementia demand a psychometrically sensitive and efficient screening procedure.