A group of researchers from Harvard Medical School and the Yale School of Medicine have debunked the idea of a “July effect” in cardiac surgery with a study of nearly half a million U.S.-based heart procedures.
The so-called “July effect”—which theorizes hospitals see worse outcomes during the transitional period after senior residents graduate from their programs and newer, less experienced candidates take their place—has been described in a handful of recent studies, first author Rohan M. Shah, MD, MPH, and colleagues wrote in the Annals of Thoracic Surgery July 25. But those projects haven’t studied the July effect in the context of major cardiac surgeries like coronary artery bypass grafting (CABG), surgical aortic valve replacement (SAVR), mitral valve repair or replacement (MVR) or isolated thoracic aortic aneurysm replacement (TAAR).
“This period has been traditionally perceived to be associated with increased patient complications and medical errors because residents lack the relevant experience in their new roles,” Shah, a cardiac surgery research associate at Brigham and Women’s Hospital, et al. wrote. “Such adverse outcomes are believed to be more pronounced in surgery given the inherent learning curve.”
Going one step further than existing studies, which have limited themselves to single institutions or the Veterans Affairs system in the U.S., Shah and co-authors isolated all CABG, SAVR, MVR and TAAR procedures recorded in the National Inpatient Sample between 2012 and 2014. The team studied overall trends in in-hospital mortality and complications for each procedure, stratifying their results by academic year quartiles (Q1-Q4) and procedure month.
In all, 301,105 CABGs; 11,260 AVRs; 54,985 MVRs and 2,655 TAARs met the study authors’ inclusion criteria. Nearly half of all CABGs, AVRs and MVRs were performed in academic Q1, while just over half—50.7%—of TAAR admissions took place in Q1.
Unadjusted in-hospital outcomes, disposition and hospital factors didn’t differ much when comparing Q1 versus Q4 admission, Shah and colleagues reported, and that included in-hospital mortality. While CABG patients admitted during Q1 incurred marginally higher costs than those admitted during Q4 ($54,310 vs. $53,223, respectively), in-hospital mortality between the groups was similar (2.4% vs. 2.2%, respectively). The authors attributed the greater costs during Q1 CABG admissions to potentially unnecessary blood tests, imaging and medications ordered by new residents and fellows.
Similarities in outcomes persisted across different cardiac procedures, the researchers said. Patients admitted for SAVR in Q1 were slightly more likely to experience post-op cardiac complications like hemopericardium or tamponade than their Q4 counterparts (14.7% vs. 13.5%, respectively), but even after risk adjustment Q1 admission failed to predict in-hospital mortality for CABG, SAVR, MVR or TAAR.
The authors did note Q1 cardiac surgery patients saw a statistically significant higher comorbidity burden than Q4 patients, but the differences were only minorly clinically meaningful. In a subgroup analysis in which they separated teaching hospitals from non-teaching hospitals, the team found teaching hospitals performed at least equivalent, if not better, than their counterparts for major surgical procedures.
“Traditionally, the notion of the July effect has been a commonly held perception among surgeons, especially given the steep technical learning curve associated with surgical training and increasing scrutiny for outcomes in the current era of value-based payment,” Shah et al. said. “Nonetheless, many critics have argued that these beliefs often tend to negatively impact resident confidence, responsibility and experience in the operating room early on in their training.”
The team said their findings highlight the “pivotal role” of appropriate resident teaching and suggest hospital support systems for new residents and fellows remain critical.
“These systems should be praised and continued to be fortified as the discipline expands to new procedures and training models,” Shah and colleagues wrote.
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.