Hip fracture complication rate associated with surgeon and hospital volume

SAN FRANCISCO — Hip fractures treated by surgeons who annually performed a high volume of these cases resulted in fewer in-hospital complications and less mortality than those treated by low-volume surgeons, according to an analysis of data from a nationwide database for almost 100,000 U.S. patients with hip fractures.

"We found that low hospital volume was associated with an increased odds ratio for infection, pneumonia, transfusion and nonroutine discharge," said investigator James Andrew Browne, MD.

Still, "Our data would suggest that mortality is more associated with surgeon volume as opposed to hospital volume," he said.

To reinforce that finding, he said the risk of death or pneumonia was greater when a surgeon only fixed zero to six hip fractures annually.

Browne presented results of the retrospective cohort study during the American Academy of Orthopaedic Surgeons 75th Annual Meeting, here.

He and two colleagues extracted 97,894 hip fracture cases from the Nationwide Inpatient Sample (NIS) database, which included patients treated from 1988 to 2002 who were older than 55 years and did not have a pathologic fracture. Patients were treated with open reduction internal fixation or hemi- or total hip arthroplasty.

Investigators placed surgeons into three groups by their annual hip fracture case volume. Low-volume surgeons completed six or fewer cases. High-volume ones did more than 16 cases.

Hospitals were also grouped into three categories, where low-volume providers completed fewer than 57 cases annually vs. high-volume providers, who did more than 132 cases.

"There is no question that [in this database] surgeon and hospital volumes were inter-related, and indeed low-volume surgeons tended to cluster at low-volume hospitals. ... However, there are significant outliers," Browne noted. Four percent of all surgeons were high-volume and practiced at low-volume hospitals; 7% of surgeons were low-volume but practiced at high-volume hospitals.

"Under multivariate analysis, low surgeon volume was associated with increased odds ratios for death, pneumonia, decubitus ulcers, transfusion and nonroutine discharge," Browne said. The risk increase was about 1.2 or 1.3, he said.

Browne was clear to point out that these conclusions were made on a single database study, and further research is required before any policy decisions should be made.

For more information:
James Andrew Browne, MD, can be reached at box 3000, Duke Clinics Building, Duke University Medical Center, Durham, NC 27710; 919-684-3170; e-mail: brown351@mc.duke.edu. He has no direct financial interest in any products or companies mentioned in this article.

Reference:
Browne JA, Pietrobon R, Olson SA. Hip fracture outcome: Are surgeon and hospital volumes important? #378. Presented at the American Academy of Orthopaedic Surgeons 75th Annual Meeting. March 5-9, 2008. San Francisco.