Until recently there was little proof that medical errors spike in the summer when new medical trainees start working at teaching hospitals - a phenomenon known as the "July effect." But a new review has found evidence that death rates do increase in July, and that many patients stay in the hospital longer than in other months.
The paper, published Tuesday in Annals of Internal Medicine, is believed to be the first systematic review of the data from previous studies. While the analysis found inconsistencies among nearly 40 studies examined, the data produced by the largest and best-designed ones indicated that patient death rates in teaching hospitals increase by 8 percent in July.
Those studies also reported longer hospital stays, more drawn-out procedures and higher hospital charges in July, when 20 to 30 percent of the more experienced doctors-in-training leave and a class of newly minted doctors starts working at teaching hospitals, said Dr. John Q. Young, the paper's lead author, who is associate program director for the residency training program in psychiatry at the University of California, San Francisco.
"This changeover is dramatic, and it affects everything," Dr. Young said. "It's like a football team in a high-stakes game, and in the middle of that final drive you bring out four or five players who never played in the pros before and don't know the playbook, and the players that remained get changed to positions they never played before, and they never practiced together. That's what happens in July."