Despite the furor c.2010 about a possible "July effect" when new interns arrive, it seems that for every article that finds major or minor differences between patient outcomes (length of stay, rate of errors, cost of hospital bill, complications, unexpected death), there is another that finds no difference.
For instance, a 2017 study of Family Medicine admissions found small increases in mortality among patients admitted with myocardial infarction in the first academic quarter of 2011 (July-September) compared with all other quarters in teaching versus nonteaching hospitals, but only increased cost and longer stay for those admitted with heart failure.
However, a larger study using data from 2010 to 2017 found no difference in adverse events in July/August compared to the rest of year once results were adjusted for patient and hospital characteristics; they looked at a range of surgical and non-surgical (MI, PNA, heart failure) diagnoses at major teaching hospitals, minor teaching hospitals, and non-teaching hospitals across. They concluded, "Patients admitted to teaching hospitals in July/August are not at increased risk of adverse events. These findings should reassure patients and medical educators that patients are not excessively endangered by admission to the hospital during these months."
Mims LD, Porter M, Simpson KN, Carek PJ. The "July Effect": A Look at July Medical Admissions in Teaching Hospitals. J Am Board Fam Med. 2017;30(2):189-195. doi:10.3122/jabfm.2017.02.160214
Metersky ML, Eldridge N, Wang Y, et al. Rates of Adverse Events in Hospitalized Patients After Summer-Time Resident Changeover in the United States: Is There a July Effect?. J Patient Saf. 2022;18(3):253-259. doi:10.1097/PTS.0000000000000887
Image credit: Seattle Municipal Archives, Doctors with patient 1999, Flickr















