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Physician warnings for unfit drivers decrease road crashes


Physicians’ warnings to patients who are potentially medically unfit to drive led to a 45 per cent decrease in serious trauma from road crashes, according to research by the Institute for Clinical Evaluative Sciences (ICES). This effect was seen after the Ontario Government introduced a financial incentive for doctors to report such patients in 2006.

“The reduction in risk is immediate, profound and sustained,” says Dr. Donald Redelmeier, lead investigator and ICES Senior Scientist. “An effect of this magnitude is about two times larger than the combined effects of modern trauma hospitals on saving people’s lives,” adds Redelmeier, also a Senior Scientist at Sunnybrook Research Institute and Professor of Medicine at the University of Toronto.

Chronic medical diseases including dementia, strokes, alcoholism and diabetes contribute to about one third of all road crashes. To prevent road crashes, physicians in Ontario provide medical warnings to patients who suffer from a condition that may make it dangerous to operate a motor vehicle. Since 2006, physicians in Ontario have received a fee of $36.25 per patient for performing this service.

The study examined 100,075 patients who received medical warnings from physicians in Ontario from April 1, 2006 to March 31, 2010 and found that:

  • Medical warnings led to a 45 per cent decrease in serious trauma from motor vehicle crashes.
  • The decrease was particularly large among elderly women with high socio-economic status, living in rural areas.
  • The decrease in risk was apparent for drivers with diverse diagnoses including alcoholism epilepsy, sleep disorders, or multiple conditions.
  • The decrease was associated with worsening depression in some patients and a decrease in return visits to the responsible physician in some cases.
  • The number of patients receiving a medical warning has almost doubled in recent years yet amounts to less than 1% of total drivers.

The public health benefits of medical warnings saved Ontario about $7 million each year by avoiding economic losses associated with motor vehicle crashes.

Ontario is the first North American region to enact payments to encourage physicians to report potentially unfit drivers. “The findings suggest medical warnings can be effective,” says Redelmeier. “The data also caution that judgment is needed to prevent an effective program being carried to excess.”

Authors: Donald Redelmeier, Christopher Yarnell, Deva Thiruchelvam, Rob Tibshirani.

The study “Medical warnings for unfit drivers and the risk of trauma from road crashes,” was published today in the New England Journal of Medicine

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.



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