Every summer, a cohort of new medical graduates enter hospital wards. One theory, dubbed the “July effect,” holds that this influx of inexperience combined with mass turnover can be dangerous, if not deadly, for patients.
The phenomenon has received considerable media attention that resurfaces every summer.
But even if the July effect seems logical, doctors and hospitals argue that the data just don't support the uniform claim that the arrival of a fresh class of interns reliably worsens outcomes for patients. Teaching hospitals and the organization that accredits them, meanwhile, have worked to address the potential for patient harm during the transition.
“The focus on training and safety is heightened in July,” said Dr. Elizabeth Mort, chief quality officer at Massachusetts General Hospital, which is affiliated with Harvard Medical School. “If there is a July effect, it can be mitigated,” she said.
When studies suggest the July effect does exist, Mort said, it's critical to ask, “Is this reproducible, generalizable? Can you really attribute it to the trainees?” And the answers might vary by institution.
Several years ago, six doctors conducted a systematic literature review on the “July effect.” They published their findings in 2011 in the Annals of Internal Medicine. The study concluded that “mortality increases and efficiency decreases in hospitals because of year-end changeovers.”
But that statement also came with a major caveat: “Heterogeneity in the existing literature does not permit firm conclusions about the degree of risk posed, how changeover affects morbidity and rates of medical errors, or whether particular models are more or less problematic.”
The authors included 39 studies in their analysis. Although each study focused on inpatient settings, they looked at varying combinations of outcomes. About two-thirds, for instance, looked at mortality, about half of them examined efficiency, and only 15% reported medical error outcomes. The authors also deemed one-third of the studies to be of higher quality because they were better designed and had larger sample sizes.
Dr. John Young, the lead author of the study, acknowledged gaps the study uncovered in the research. “Is it an effect seen across the board? Or is it more likely to occur in certain situations and not others?” he asked. “It's probably that there are certain types of procedures and settings where the risk is higher, but we don't know what those are.”
Studies focusing on specific patient populations and procedures have found conflicting evidence.
A study published in the journal Circulation in 2013 examined high- and low-risk acute myocardial infarction (heart attack) patients. For those in the highest quartile of risk, adjusted mortality rates were higher in July (22.7%) than in May (18.8%) in teaching-intensive hospitals than they were in non-teaching-intensive hospitals. The researchers did not find any difference, however, for low-risk patients.
Another study, published in 2014 in the Canadian Journal of Surgery, found that patients undergoing cancer surgery in academic medical centers had no difference in overall postoperative complications or in-hospital mortality rates in July. Spinal surgery patients suffered “a minor to negligible July effect,” researchers determined in a study published in the Journal of Neurosurgery in 2013.
In the five years since Young's review of the research, many hospitals have increasingly emphasized quality and safety, including by intensifying the supervision and training of new interns. It is this “somewhat uncontrolled environment,” Young said, that renders designing a study to discern the impact of the mass entrance of new interns—and whatever training they receive—so difficult.
At Massachusetts General Hospital over the past decade, the hospital has implemented increasingly “robust” orientation and trainings that take place online and in person, according to Mort. These programs are part of a hospital-wide shift.
“It's not just the interns,” Mort said. “The whole organization has prioritized quality and safety.”
Doctors and administrators at several other major teaching hospitals said they had not seen evidence of a general “July effect” in their institutions. They too cited training programs and heightened attention to quality and safety, tied in part to changes implemented several years ago by the Accreditation Council for Graduate Medical Education.
At Yale-New Haven (Conn.) Hospital, training for interns covers everything from hand hygiene to advanced cardiac life support, said Dr. Thomas Balcezak, the hospital's chief medical officer. Depending on their specialties, some new residents go through simulations, such as how to insert an IV. With residents hailing from many different medical schools, this orientation helps bring everyone up to speed.
Yale-New Haven has carefully examined its performance measures, Balcezak said, and hasn't identified any variation that correlates to the arrival of new trainees in July. “I don't think that the data is there to make that general sweeping conclusion,” he said.
The fact that the July effect seems intuitive, or logical, doesn't make it real, Balcezak added. “I think in general in medicine you always have to be careful about making conclusions about things because you think it makes sense.”
Dr. Catherine Skae, vice president for graduate medical education at Montefiore Medical Center in New York City, acknowledged that “common sense tells us there's a huge vulnerability at this time of year, when you have across the nation thousands of newly minted doctors starting.”
But Montefiore's data do not suggest a July effect, said Skae, who last year scoured several years' worth of data for human errors by trainees. Concerns about preventing medical errors should not be limited to July, she added. “It's truly our responsibility to be hypervigilant throughout the year.”
At NYU Langone Medical Center, "the July effect has been talked about a lot but in reality has been found to be negligible," although a small portion of the highest risk patients may be affected, said Dr. Fritz Francois, chief medical officer and patient safety officer.
Hospital administrators asked about the July effect frequently cited changes made by the ACGME as spurring increased attention to intern training and supervision.
In 2012, the organization created the Clinical Learning Environment Review program, which involves biannual visits to ACGME-accredited teaching hospitals and other clinical learning centers. The ACGME then delivers feedback to organizations in six areas, including patient safety, although their accreditation status is not affected by the findings from CLER visits.
"What we are doing as an organization is driving change by providing that information and then coming back two years later to see what's changed," Dr. Kevin Weiss, the ACGME's senior vice president for institutional accreditation, said of the CLER program.
In 2011, as part of its accreditation requirements, the ACGME also defined specific levels of supervision for residents, including interns.
Whether patients believe in the July effect or not does not appear to have an impact on hospital visits, numerous hospital administrators said.
“We're as busy as we always are,” Skae said of Montefiore in July. “People get sick, and if they need care, they're coming in.”