July Brings a Spike in Temperatures-and Fatal Drug Errors

For counties that have teaching hospitals, July means more than just warmer weather. These areas experience a 10% rise in fatal drug errors, according to research published in the Journal of General Internal Medicine, which also suggests that the more teaching hospitals a region has, the more fatal drug errors occur during that month.

David Phillips of University of California at San Diego and Gwendolyn Barker of University of California at Los Angeles conducted a study to determine whether the influx of new medical residencies in the month of July leads to increased errors and a decline in patient outcomes—what is known as the “July Effect.”

Phillips and Barker examined all U.S. death certificates from 1979 to 2006, comparing the observed number of deaths in July with the number expected, determined by least-squares regression techniques. They also determined that fatal medication errors increased by 10% in July—and in no other month—inside medical institutions, in counties teaching hospitals. In contrast, there was no July spike in counties without teaching hospitals.

“After assessing competing explanations, we concluded that the July mortality spike results at least partly from changes associated with the arrival of new medical residents,” said the investigators.