July 31, 2019
A new study study debunks the "July effect" – a popular theory that medical errors are more likely to happen in the month of July due to the influx of medical school graduates. Researchers say it is not true — at least not for heart surgeries.
According to a new study published in The Annals of Thoracic Surgery, researchers from Brigham and Women's Hospital and Harvard University examined more than 470,000 standard cardiac procedures.
The surgical procedures were one of the following: a coronary artery bypass graft, surgical aortic valve replacement, mitral valve repair or replacement or isolated thoracic aortic aneurysm replacement.
The study found that the mortality rates for each procedure did not vary by the month or quarter in the academic year during which they were performed. There were no observed differences in complications, costs, or length of hospital stay. The study also concluded that teaching hospitals had a lower adjusted mortality rate than non-teaching hospitals for surgical aortic valve replacement and mitral valve repair or replacement procedures.
Researchers looked at the data for 301,105 coronary artery bypass grafting procedures; 111,260 surgical aortic valve replacements; 54,985 mitral valve repairs or replacements; and 2,655 isolated thoracic aortic aneurysm replacement procedures.
They compared yearly data by examining the academic year by quarter: Quarter 1, July to September, when residents were the least experienced, to Quarter 4, April to June, when the residents were the most experienced.
The procedures took place between 2012 and 2014 on adult patients and were surveyed using the Nationwide Inpatient Sample, a database that provides information from more than 35 million hospital admissions.