Fitness to drive requires more objectivity


By Mardi Chapman

5 Jun 2019

A practical decision tree for assessing fitness to drive in people with epilepsy has been shown to be effective in removing some of the subjectivity inherent in certification by treating doctors.

The decision tree streamlines the assessment into 13 yes/no questions consistent with Australian fitness to drive standards.

A pilot study compared the findings of usual annual medical reviews in 253 people with epilepsy and use of the decision tree performed by the same doctors.

Data from the returned decision tree forms was entered by non-medical staff at the driver licensing authorities in NSW and Victoria and used to recommended periods of seizure freedom for individual patients.

The average time required for doctors to complete the decision tree was 5.4 minutes. Most were completed by GPs.

The study found while all drivers were considered fit to drive by their doctors at medical review, only 88% were fit to drive based on the decision tree.

About 6% of people were considered unfit to drive, 4% were referred for further review and 2% of returned forms were unusable.

Most disagreements between the output of the decision tree and the doctor’s initial assessment were related to the time since last seizure (50%) or planned medication withdrawals (31%).

“Five patients were considered by their physician fit to continue driving despite planned withdrawal of therapy, and two were considered fit despite the physician considering that the factor provoking their last seizure was likely to recur,” the study said.

“A further patient had seizures that the physician felt did not impair consciousness and therefore did not render the driver unfit, but it had not been verified by witnesses or video‐electroencephalographic monitoring, as required by the national standards.”

“One driver had been involved in a crash due to a seizure within the past 12 months. None of these drivers met the published standards, and their physicians did not offer any comment as to why they should be allowed to drive.”

Author of the paper Associate Professor Ernest Somerville, representing the Driving Committee of the Epilepsy Society of Australia, told the limbic that doctors were often “liberal” towards their patient’s wishes to keep driving.

The relationship between the doctor and the patient could make it difficult to be objective and result in unsafe decisions.

It was strong reason to remove the ultimate decision from the hands of doctors to driver licensing authorities and instead use a tool such as the decision tree to provide clinical data rather than opinion.

Associate Professor Somerville said the decision tree was in use in NSW and South Australia and other jurisdictions had been approached to consider its role.

“It does increase the workload and it does increase the responsibility that they have to take so it’s not necessarily attractive to them. The safety aspect is really the key issue that should influence their decision to accept this kind of system or not.”

He said the decision tree was dependent on the accuracy of the information that the patient provides.

“And if people really depend on their driving licence, there is an incentive to give answers that are going to allow them to keep driving.It’s a very sensitive issue with patients.”

He added that epilepsy was a bit different from other medical conditions related to driving.

“The impairment that people have is intermittent so for most of the time, people with epilepsy are perfectly safe to drive. But when they have a seizure they are profoundly impaired.”

“And if they have a seizure the crash rate is about 50% and the crashes can be more severe than your average crash because there is no evasive action taken and sometimes during a seizure their foot will go down on the accelerator as their leg stiffens so they accelerate rather than brake.”

He said reviews had to be done by an independent person and the people best qualified to do that were neurologists.


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