Doctors warn medically unfit not to drive

Requiring Ontario physicians to report patients medically unfit to drive led to a 45 percent drop in serious road crashes, U.S. and Canadian researchers found. Lead author Dr. Donald Redelmeier of the University of Toronto and Robert Tibshirani of Stanford University, and colleagues tracked 100,075 patients in Ontario, age 18 and older who received medical warnings from 2006 to 2010 not to drive. The analysis, published in the New England Journal of Medicine, indicated a 45 percent reduction in the risk of road crashes resulting in emergency department visits in the year following the warnings. "We found these warnings were more powerful than warnings about smoking, diet and exercise, and about two times larger than the combined effects of modern trauma centers at saving people's lives," Redelmeier said in a statement. "The data suggest that practicing physicians may be able to help prevent serious trauma from road crashes -- medical warnings about driving are taken seriously by patients." In the study, 95 percent of those patients who received warnings had at least one of the 20 most common diagnoses that might indicate problems with driving, and 21 percent had at least five of the diagnoses that justified a warning -- alcoholism, epilepsy, dementia, stroke and sleep apnea. Prior to warnings, the patients had a total of 1,430 crashes in a three-year period, averaging about 466 per year. In the year post-warnings, the rate dropped to about 273 road crashes. Redelmeier described the decrease as "immediate, profound and sustained," particularly among drivers who had multiple diagnoses.