In the section on identifying patients with progressive dementia, the guide indicates that "individuals showing a score of less than 24 on this test [the Mini-Mental State Examination] are ineligible to hold a driver licence of any class pending complete neurological assessment."

Use of a specific score as a cut-off for this examination has never been validated because it is only a screening instrument with a specificity and sensitivity in the range of 85%. As the authors of the guide state, the test can be affected by language difficulties, lack of education and an age of more than 85 years.

In the current format, with the above explicit statements, are physicians liable legally if their patients with a score of 23 are responsible for an accident? The guide is also not clear on what is meant by a complete neurological assessment. Does it mean that all patients with a score of less than 24 need to be referred to a neurologist? This guideline seems not only scientifically unsupported but also legally charged.

With the greying of Canada, we urgently need a scientifically sound and well-validated assessment tool to evaluate fairly the increasing number of Canadians with cognitive deficits who may be at risk, and may be putting others at risk, while driving.