Driving Debate: Reporting Motorists With Medical Conditions Contested at CCC Meeting

Marlene Busko

November 01, 2012

TORONTO — Legislation in most Canadian provinces and six US states requires physicians to report drivers with serious medical conditions to motor-vehicle registries, yet the consensus at an entertaining debate here at the Canadian Cardiovascular Congress 2012 was that doing so won't make roads safer [1].

Both debaters ultimately agreed that there is little evidence that by reporting drivers with serious medical conditions, cardiologists and other physicians will lower the rate of motor-vehicle accidents. Dr Carlos Morillo (McMaster University, Hamilton, ON) attempted to persuade the audience that physician reporting does indeed make roads safer.

He presented a complex "driving-impairment" formula from the Canadian Medical Association and guidelines developed by the Canadian Cardiovascular Society (CCS) that recommend that physicians should report patients with syncope or other cardiovascular disease to the Ministry of Transportation.

However, cardiac conditions do not always translate into a driving hazard. For example, he noted, a study investigating ICD shocks showed that although patients had an increased risk of having a shock in the 30 minutes after driving, this was not true while driving.

On the other hand, a recent study published in the New England Journal of Medicine [2], which looked at almost 100 000 patients from an Ontario database, came to a sensational conclusion: "Warnings to patients who are potentially unfit to drive may contribute to [about a 45%] decrease in subsequent driving impairment."

But as a colleague told him, "I suspect that taking any group of drivers would have the same effect--you don't drive, you don't crash."

"We don't have very good evidence, but we know [car crashes] happen, Morillo concluded. One life lost is one life too many, but motor-vehicle accidents are unpredictable. Nevertheless, clinicians are still mandated to report most of these medical conditions--whether it's going to make roads safer or not, he said.

Quashing the Statement . . . 

Arguing convincingly that physician reporting does not increase public safety, Dr Christopher Simpson (Queen's University, Kingston, ON) said that car accidents are largely caused by alcohol, as well as poor road conditions, inattention, "basic stupidity," using (even hands-free) phones, and speeding.

A study based on 2004 Ontario data showed that in a population of about 12 million, there were 1251 fatal collisions, of which 20 (1.6%) were caused by drivers with a medical illness. Medical conditions accounted for 0.4% of the 102 000 accidents that caused personal injury and 0.1% of the 316 000 collisions that caused property damage.

"In a perfect system . . . if we could remove anyone destined to have a crash because of medical illness, we would reduce motor-vehicle accidents by 1%--just a tiny sliver," Simpson said.

Can you think of a single drug that you would give to 18 000 patients, which would cause side effects in every one of them, to save one life?

If physicians reported all patients who had one of the top six cardiac diseases and these patients stopped driving, they would need to report 18 000 patients to save one life, he continued. "Can you think of a single drug that you would give to 18 000 patients, which would cause side effects in every one of them, to save one life?" he asked.

Mandatory reporting may do more harm than good. For example, a study of epileptic patients showed that patients who lived in areas with mandated physician reporting were less likely to disclose that they had experienced a seizure, and thus they missed out on treatments.

Expanding on this dilemma, Morillo told heartwire that "the problem is we don't have enough evidence that taking away the driver's license makes the roads safer." The guidelines are a bit vague, although there is a clearer need to report certain types of patients--such as those with defibrillators or certain types of syncope, he noted.

Simpson admitted to heartwire that he and his debating opponent "are on the same page. . . . We all have a bit of discomfort reporting patients, because unlike everything else we do for patients, we're actually working against them."

He is an author of the CCS consensus conference 2003 guidelines, "Assessment of the cardiac patient for fitness to drive and fly," which are available online and as a smartphone app. "But I'll be the first to admit, there are really no good trials," he confided.

Dr Andrew Krahn (University of British Columbia, Vancouver) told heartwire that "the reality is that most people are not reported . . . for three reasons: the process is onerous, our medicolegal system doesn't usually result in a lot of retribution, and the healthcare team is cynical [about whether] these patients really do pose a risk to the public."

The authors declared they have no conflict of interest.