Does Experience Matter? Study Finds Same Mortality Rates For Experienced and New Surgeons

Are the patient outcomes of newly trained surgeons comparable to the outcomes of experienced surgeons performing the same types of surgery at the same hospitals? A new study examined this question and came to a surprising conclusion: there were “no statistical difference between the patient mortality rates of new and experienced surgeons.” 

Researchers at the University of Pennsylvania went to great lengths to make sure they only tested for a surgeon’s “experience.” The study summary (available here) briefly describes the statistical method the researchers employed:

[T]he research team accessed a Medicare database from several states covering a period of two years to create two matched groups of surgical patients. The data consisted of 130,106 patients who were operated on in 498 hospitals. The two groups created through the matching process consisted of 6,260 surgical patients each and were similar in 2.9 million categories. For example, each group had the same number of patients who received each surgical procedure (i.e., knee replacement, appendectomy). Additionally, among patients who received a particular procedure, the numbers of patients who had a particular pre-existing condition (i.e., diabetes, past stroke, and high blood pressure) also were as close as possible across the two groups. “Matching” patients in this way makes it easier to compare the clinical outcomes of the two groups.

After breaking down the two groups into 6,260 patients for both newly trained and experienced surgeons, the researchers found that the mortality rate for patients of experienced surgeons was 3.59% (225 deaths out of 6,260 surgeries), while the mortality rate of new surgeons was 3.71% (232 deaths out of 6,260 surgeries).

UPenn researchers involved in this study included Dr. Rachel R. Kelz, associate professor of surgery; Dr. Jeffrey Silber, professor of pediatrics, anesthesiology and critical care; Paul Rosenbaum, professor of statistics; and Sam Pimentel, a doctoral student in statistics. 

This results of the study suggest at the very least that surgeons are very well-trained before undertaking their first procedures. However, the study does have some notable limitations, as Dr. Kelz indicates. 

“It is reassuring that new surgeons were able to achieve similar mortality rates to experienced surgeons when caring for similar patients. However, mortality is a relatively rare event that may not expose the benefits of experience,” she states. “Therefore, future studies focused on additional outcomes are needed to ensure that new surgeon training and transition to independent practice are appropriately structured to meet the surgical needs of the public.” 

Specifically, “[b]ecause surgical training was radically changed in recent years—including a reduction of six to 12 months of training time—and other factors, the research team said further study will be needed to ensure the findings generalize.”

Indeed, perhaps more impressive than this study’s findings are the possibilities for future research using the new statistical methodology. “The new techniques developed for this study have tremendous promise to enable large-scale comparisons across a variety of health care settings and populations with appropriate control for differences in patient cohorts that was not previously possible,” states the article. 

View the full article, available in the Journal of American Statistical Association. 

View the press release here.