How much does experience matter?

When it comes to medical care, many people think it is of the utmost importance, as inexperienced healthcare providers are considered a possible source of potentially life-threatening errors. In fact, it is commonly believed that being admitted to an American hospital in July, when newly graduated interns, residents, nurses, and other new medical workers first report to work, will almost guarantee a poor level of care. In particular, teaching hospitals experience a 'cohort turnover' when all the experienced trainees depart at the same time new trainees enter, an annual changeover that affects more than 100,000 staff members in the U.S. and 32,000 in Europe.

In the United Kingdom, this migration of talent is known as the 'August killing season' while in the U.S. it is referred to as the 'July effect.' Many studies have examined patient outcomes to understand whether the 'July effect' is real or simply an imagined threat.

Recent Evidence

To explore this question, researchers from the Mayo Clinic analyzed outcomes of one million spinal surgery patients admitted to 1,700 hospitals across the country during July over an eight-year period. The researchers identified spinal surgery hospitalizations from the 2001-2008 Nationwide Inpatient Sample (NIS) hospital discharge database. The NIS is the largest all-payer inpatient database in the U.S. that analyzes national trends in health care utilization outcomes. Of the total data analyzed, roughly half of the spinal surgeries were performed in July at teaching hospitals, facilities typically affiliated with a medical school where students get their first on-the-job training, while the remainder were performed during other months at non-teaching facilities.

Compared with those admitted in other months, patients admitted in July to teaching hospitals fared only slightly worse (statistically negligible) in terms of in-hospital death rates, postoperative surgical complications, and negative reactions to implanted devices. In fact, a July effect was not observed in higher-risk patients, patients who were electively admitted, or patients who underwent a simple spinal procedure. However, July patients experienced a significantly higher likelihood of discharge to a long-term care facility, postoperative infection, and a failure of their surgical stitching compared with other months.

Although such experiences do not contribute to death rates, the effects may impact longer-term health outcomes for individual patients. Perhaps subtly, then, the findings of this study align with older research on the matter of experience.

Previous Studies

Researchers at the University of California examined the relationship between inexperience and error by studying changes in the number of medical mistakes made during July, when thousands begin residencies and fellowships. Unlike other studies, they focused on fatal medication errors — an indicator, they believed, of an important medical mistake. To conduct their study, they examined all official U.S. computerized death certificates, a whopping 62,338,584 records. Their dataset begins in 1979, when hospital status was first recorded, and ends in 2006, the latest data year available.

What did they find? They discovered previously unknown evidence for a July spike in fatal medication errors. In fact, July mortality from medication errors was 10 percent above the expected level. To further explore the question of a 'July effect,' the researchers hypothesized other possibilities for the evidence they found. Namely, they questioned whether a 'July Effect' might result from behavioral changes occurring during the summer, including a possible upsurge in summer alcohol consumption (combined with harmful alcohol-medication interactions), a summer increase in injuries from accidents and other external causes (combined with increased medical efforts, such as prescriptions, to treat these injuries), and an increase in summer tourism (tourists may receive worse health care).

However, an 'August spike' was never discovered nor did the researchers find a general summertime increase in medication errors. "At present, the New Resident Hypothesis is the best available explanation for our findings," the researchers concluded.

Unfortunately, they echo fellow researchers who conducted a similar search of English-language reports published between January 1, 1989, and July 1, 2010 to investigate a potential 'July effect.' Having concluded that mortality increases and efficiency decreases in hospitals because of year-end changeovers, the researchers who published their findings in 2011 acknowledged that "heterogeneity in the existing literature does not permit firm conclusions about the degree of risk posed, how changeover affects morbidity and safety, or whether particular models are more or less problematic." Further investigation, both sets of researchers decide, is needed.

Alternative Findings

Finally, a group of researchers in Texas chose to limit their findings to cardiac surgery outcomes when studying the "July effect." They accomplished this by collecting data from the Department of Veterans Affairs Continuous Improvement in Cardiac Surgery Program and identifying 70,616 consecutive cardiac surgical procedures performed between October 1997 and October 2007. Once they assembled their dataset, they compared the morbidity and mortality rates for 11,975 operations performed from July 1 to August 31 and 58,641 operations performed from September 1 to June 30.

What did they find? Although the two patient groups had similar demographic and risk variables — isolated coronary artery bypass grafting accounted for 76.7 percent of early-period procedures and 75.8 percent of later-period procedures — the morbidity rates did not differ significantly between the early and late periods. And the operative mortality was also similar. However, the early part of the academic year was associated with slightly longer operating times. In short, their findings, which concern only cardiac procedures, are more hopeful.

Ultimately, when considering a potential 'July effect' on either a macro or a micro level, two easy solutions present themselves. If hospital administrators question whether a "cohort turnover" might cause a greater number of healthcare mistakes or potentially deaths, then they should find a way to stagger the entry of new workers. And if any doubt exists in an individual's mind as to whether experience matters when it comes to medical care, then simply avoid the hospital, if possible, during July.

Sources: Young JQ, Ranji SR, Wachter RM, Lee CM, Niehaus B, Auerbach AD. "July Effect": Impact of the Academic Year-End Changeover on Patient Outcomes. A Systematic Review. Annals of Internal Medicine. 2011.

Bakaeen FG, Huh J, LeMaire SA, et al. The July Effect: Impact of the Beginning of the Academic Cycle on Cardiac Surgical Outcomes in a Cohort of 70,616 Patients. The Annals of Thoracic Surgery. 2009.

Phillips DP, Barker GEC. A July Spike in Fatal Medication Errors: A Possible Effect of New Medical Residents. Journal of General Internal Medicine. 2010.

McDonald JS, Clarke MJ, Helm GA, Kallmes DF. The effect of July admission on inpatient outcomes following spinal surgery. Journal of Neurosurgery: Spine. 2013.