However, it is impractical to suggest to physicians that all patients with suspected cognitive difficulty be referred for a standardized on-road, or even simulated, evaluation. Doctors in clinical practice need a screening tool to assist decision-making. Despite the above-mentioned concerns, the Mini-Mental State Examination has been shown to correlate with on-road driving test results,³ and poor performance on parts of the Mini-Mental State Examination correlates with the risk of adverse driving events.⁴ Decisions concerning driving aptitude must often be made on uncertain grounds. It should be noted that the statement referenced by Byszewski and Dalziel is a direct quotation from the standards found in the National Safety Code⁵ developed by the medical consultants for the provincial and territorial driver licensing authorities. Extracted from the context of the National Safety Code quotation, the statement quoted by Byszewski and Dalziel on the Mini-Mental State Examination test scores reads as a hard-and-fast rule; the CMA guide⁶ specifically mentions that physicians should consider the impact of education and language on test results.

As noted in the CMA guide,⁶ liability can result when physicians fail to report potentially medically unfit patients if these patients subsequently have an accident and cause harm to others. The Mini-Mental State Examination is one tool for identifying potential unfitness to drive. Physicians, especially where there is a mandatory reporting system, should err on the side of caution and report potentially medically unfit drivers.⁶ A physician could deem a patient potentially unfit even without the administration of the Mini-Mental State Examination. It is only one tool to assist physicians in determining medical fitness to drive.