Specifically, the researchers found that diabetics experienced one additional day of hospitalization (an average of 4.7 vs. 3.6 days) with costs approximately 20 percent higher ($12,898 vs. $10,794). Additionally, diabetics had higher mortality rates (0.26 percent vs. 0.11 percent) and higher rates of post-operative complications (4.63 percent vs. 3.27 percent).
Demonstrating this link between diabetes and worse outcomes is important, the researchers said, because ankle fractures are one of the most common injuries treated by orthopedic surgeons, and the study's findings provide guidance on how to improve the care for these patients and reduce health care expenditures.
The results of the Duke analysis were published Aug. 15, 2005, in the Journal of Bone and Joint Surgery.
"While a number of smaller studies have indicated that diabetic patients tended to have worse outcomes after ankle surgery, this is the first large-scale analysis of a cross-section of patients across the U.S.," said Shanti Ganesh, M.P.H., lead author of the study and fourth-year year medical student at Duke University School of Medicine.
"This analysis demonstrated that diabetic patients, no matter how severe the ankle fracture, were more likely to experience higher rates of post-operative complications, mortality, and non-routine discharge, with accompanying longer lengths of hospital stay and higher hospital charges," Ganesh said.
For their analysis, the Duke team consulted the Nationwide Inpatient Samples (NIS) database and identified 169,598 patients who underwent surgery for ankle fractures. The NIS, sponsored by the U.S. Agency for Healthcare Research and Quality, is a publicly available database of more than 8 million patients from more than 1,000 U.S. hospitals. The hospitals vary by region, size, location, teaching status and ownership.
"The strength of this analysis is that it provides a nationally representative and real-world picture of what happens to ankle fracture patients in the U.S.," said Ricardo Pietrobon, M.D., senior member of the research team and director of Duke's Center for Excellence in Surgical Outcomes (CESO), which supported the analysis. "We were unable to extrapolate from the data gathered from smaller, single-center studies what the situation was nationwide.
"Now we have specific data that allows us to quantify the added risks and costs of diabetes for these patients," Pietrobon continued. "This information is crucial in improving outcomes and quality of life for our patients undergoing surgery to repair ankle fractures."
Of the 169,598 ankle fracture patients, the Duke team identified 9,174 (5.71 percent) with diabetes. The diabetic patients tended to be more than 10 years older than the non-diabetic patients, and when they did suffer ankle fractures, they tended to be more severe than those suffered by non-diabetic patients.
Ganesh said that the results of the study indicate that physicians taking care of ankle fracture patients should appreciate the effect that diabetes can have on the treatment and recovery of their patients. Strategies could include close monitoring of glucose levels during and after surgery and the prophylactic use of medications to prevent the formation of deep venous thrombosis (DVT), which can occur in surgery patients who are bedridden for extended periods of time.
It is also widely appreciated that diabetic patients tend to have slower healing rates than non-diabetic patients, Ganesh continued. This can be important not only during hospitalization, but also after discharge, when patients typically begin rehabilitation activities, she added.
One interesting finding, which the researchers said was not a focus of the current study and confirms other findings, was that the percentage of patients with diabetes steadily increased over the 12-year period from 1988 to 2000.
The researchers estimate that of the 260,000 Americans who fracture their ankles every year, about 25 percent will require surgery to stabilize the ankle.
Other Duke members of the team, in addition to Ganesh and Pietrobon, were Deng Pan, Nina Lightdale, M.D. and James Nunley, M.D. William Cecilio, Catholic University of Parana, Brazil, was also a member of the team.