Don’t get sick in July. It could kill you.

Avoid hospitals in July like the plague.

July is the worst time to be in a hospital.

These are some of the headlines that seem to pop up every time July 1 rolls around.

That date is important because it’s when first-year residents report to work at teaching hospitals around the country.

Often referred to as the “July Effect,” the phenomenon implies that the influx of inexperienced first-year residents, or doctors, makes it unsafe for patients who are admitted to teaching hospitals during that month.

“There is a large number of inexperienced physicians in the nation’s teaching hospitals in July,” said Dr. Janis M. Orlowski, chief healthcare officer for the Association of American Medical Colleges. “No doubt about it.”

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Is ‘July Effect’ real?

Dr. Jessica Bienstock, M.P.H., is a professor of gynecology and obstetrics, and the associate dean for graduate medical education at the Johns Hopkins University School of Medicine.

This year approximately 1,100 residents are under her watch.

“I don’t think the July Effect exists,” she said. “I think it’s an urban legend.”

Dr. Clarence Braddock, vice dean for education at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA), oversees more than 1,000 residents and fellows at the hospital.

“There have been some studies [about the July Effect],” he said. “On balance the effects they are giving are so small it’s not conclusive.”

Studies about this phenomenon are mixed. Some suggest a 4 to 10 percent bump in mortality rates starts in early July. Other studies say it’s nearly nonexistent.

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Different studies, different results

In 2005, the National Bureau of Economic Research conducted one of the most comprehensive studies on the July Effect, titled "Cohort Turnover and Productivity: The July Phenomenon in Teaching Hospitals.”

The authors culled data from 700 hospitals from 1993 to 2001. They concluded that both minor and major teaching hospitals saw “an increase in risk-adjusted mortality of roughly 4 percent in the July-August period.”

This amounts to about 1,500 to 2,700 “accelerated deaths per year” because of the July Effect, according to the report.

However, a 2013 study published in the journal Circulation found scant evidence of the July Effect.

From 2002 to 2008, the authors looked at the “percutaneous coronary intervention (PCI) rates, and bleeding complication rates, for high and low risk patients with acute myocardial infarction (AMI)” admitted to 98 teaching hospitals, and 1,353 nonteaching hospitals, from May to July.

Researchers said that “high risk AMI patients experience similar mortality in teaching- and nonteaching-intensive hospitals in July,” and that “low risk patients experience no such ‘July Effect’ in teaching-intensive hospitals.”

The analysis, though, did state that there is “lower mortality in teaching-intensive hospitals in May,” compared to July.

Another 2013 study, conducted over eight years, looked at the outcomes of 1 million spinal surgery patients at 1,700 hospitals in the United States during July. Half of the patients had surgery at teaching hospitals while the other half had surgery at nonteaching facilities.

Researchers concluded that patients “at teaching hospitals fared only slightly worse” — a “negligible effect,” based “on criteria such as in-hospital death rates and negative reactions to implanted devices.”

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What new residents offer

So what do first-year residents bring to their new jobs in terms of experience? And what kinds of responsibilities are put upon them?

All three experts Healthline spoke to offered similar scenarios.

New residents tend to come with two years of hospital experience under their belts. This occurs during their third and fourth years of medical school, when they rotate through various hospital departments.

First-year residents are assigned to teams within the field of medicine they plan to practice. A team includes midlevel and senior residents, plus an attending physician.

So the notion that interns are wandering the halls with no supervision, making grave and fatal mistakes, is misleading, according to Orlowski.

“Today, medicine is practiced as a team sport,” she said.

Bienstock said that residents do assess patients, conduct exams, and perform other crucial components required by any doctor, but they always consult their supervisors. Supervision is constant, and feedback is ongoing.

She argued that if anything, patients at teaching hospitals tend to get exceptional care because of the sheer volume of medical experts on-site.

“New residents are so well supervised,” she said. “We have attending doctors in the hospital 24/7. If there is a true emergency, the most senior people go in.”

Orlowski added that if issues come up, residents are quickly referred to simulation labs. This entails anything from getting feedback on patient assessments, honing surgery skills on dummies, or training on some of the increasingly complex equipment.

“In medicine we have a phrase. It’s called ‘lifelong learning,’” she said. “I’m still required to get medical education and different training.”

Bienstock said it’s important for people to know that an overriding priority for all hospitals is patient safety. That is the foundation of all residency programs.

“Yes, new doctors are learning, but they are never by themselves,” she said. “Patient safety is the most important thing.”

Braddock, who has been practicing medicine for over 25 years, concurred.

“The amount of redundancy and oversight has been so significant, I don’t worry about safety,” he said.

Orlowski added that each year as a new crop of residents enter the workforce, she is consistently inspired by their dedication and hard work.

“They are some of the smartest people around. They want to be good doctors,” she said. “I always think, ‘lucky for us.’”