Crash rates of quebec drivers with medical conditions.

Using a databank that combines comprehensive medical data with the driving records of 96% of the drivers in Quebec, odds ratios were calculated for crash risk involving death or serious injury according to the diagnosis of medical conditions traditionally associated with increased crash risk. Results were controlled for age, sex, residence (rural/urban), possession of a professional licence (classes 1 - 4), previous involvement in a crash with injury or death and for the presence of other medical conditions. In addition, crash risk was calculated for drivers with multiple conditions. There was a slight to moderate increase in crash risk for most of the conditions and an incremental increase in crash risk as the number of conditions increased.