Hospitals with higher surgical volumes less likely to cause unintentional serious injuries

Stanford University School of MedicineSep 2 2011

Are you scheduled for heart bypass surgery or weight loss surgery? You might want to find out just how frequently different hospitals in your area are performing those procedures before deciding where to go. A new study finds that hospitals with higher surgical volumes for certain procedures are less likely to cause unintentional serious injuries to hospitalized patients when compared to those hospitals that perform the procedures less often.

"We found a linear relationship between hospital volume and patient safety," said lead author Tina Hernandez-Boussard, Ph.D. "That means that the more procedures these hospitals were performing, the lower rates they would have of adverse events."

Hernandez-Boussard and colleagues are at the Stanford University School of Medicine. The study appears online in the journal Health Services Research.

The researchers used data from the Nationwide Inpatient Sample discharge database, a large national inpatient database. They looked at the rates of nine different adverse events in hospitalized patients following three different high-risk procedures — abdominal aortic aneurysm repair, heart bypass surgery and gastric bypass surgery. Examples of adverse events included blood infections, blood clots after surgery, postoperative bleeding, accidental punctures and death among surgical patients.

The investigators defined low surgical volume as fewer than 28 procedures per year for abdominal aortic aneurysm, fewer than 245 for heart bypass surgery and fewer less than 89 for gastric bypass surgery. In almost all instances, hospitals with higher surgical volume had fewer adverse events than hospitals with low surgical volume.

David Bates, M.D., executive director of the Center for Patient Safety Research and Practice and chief of general internal medicine at Brigham and Women's Hospital, said, "One question has been, what's the minimum number of cases that a hospital needs to do to be safe? That's been tricky, because the implication is that below a certain level, hospitals shouldn't be doing the procedure." Bates has no affiliation with the study.

"For a procedure that's high risk, I think it's important to do it at a place that does sufficient volume so that you have the best chance for a good outcome," Bates said. In addition to the surgeries included in the study, high-risk procedures include pancreatic cancer surgery, esophageal cancer surgery, complicated birth deliveries and others.