Determining medical fitness to drive: physicians need support

In Ontario, as in six other Canadian provinces, mandatory reporting of patients considered to be potentially medically unfit to drive has been introduced as one means of addressing this issue. In their case-series analysis of drivers involved in a motor vehicle collision and subsequently admitted to an Ontario trauma unit for treatment, Redelmeier and colleagues demonstrate that, despite legislated requirements, only 3% of potentially medically unfit drivers had been reported to licensing authorities.1 They conclude that medically unsafe drivers are rarely reported to licensing authorities despite having been seen by a physician. Clearly, this under-reporting is a concern, since drivers with reportable conditions were involved in collisions causing injury and death. Research has generally demonstrated that physicians have limited training and knowledge with regard to assessing medical fitness to drive.2,3 Many medical conditions are associated with an overall increase in collision risk; these conditions include alcohol abuse and dependence, cardiovascular and cerebrovascular disease, psychiatric disorders, dementia, diabetes mellitus, epilepsy, obstructive sleep apnea and vision disorders.4 However, at the level of the individual patient, it remains challenging to assess the impact of a particular condition on driving ability. For instance, the spectrum of disease for a condition such as diabetes mellitus can range from a newly diagnosed condition controlled by diet to a long-standing condition requiring medication as well as involving complications such as neuropathy, retinopathy and vascular disease. At some point the impairments associated with diabetes mellitus may affect driving ability, but the challenge for the physician lies in determining when to intervene or report. Redelmeier and colleagues’ findings point to a particular challenge for physicians, in that the primary reportable conditions of alcohol abuse and cardiac disease (95% of the reportable conditions identified) belong to the category that Dobbs refers to as acute conditions whose effect on driving is sporadic or unpredictable. For example, the typical concern with cardiac conditions with respect to driving would be loss of consciousness. In contrast, neurological conditions (21% of those reported by Redelmeier and colleagues) tend to have chronic, continuous effects that could affect driving ability and are often best assessed by a direct on-road evaluation. That being said, these chronic conditions may be more likely to be considered by physicians in the primary clinic setting, since the potential impact on driving ability may be more evident. As the present researchers and others point out, continuing barriers to physician reporting include the lack of valid tools for physicians to use in determining medical fitness to drive.1,6 Although this study demonstrates that there is clear under-reporting by physicians of relevant medical conditions, this does not mean that mandatory reporting should necessarily be abandoned. Identifying the ineffectiveness of mandatory reporting allows for a review of strategies to improve the identification of persons who may be medically unfit to drive. Clearly, this research reveals that the most prevalent condition is alcohol abuse and dependence and that strategies to address this condition specifically are warranted. On an optimistic note, resources to support physicians in determining medical fitness to drive are becoming in-