Hospitals with higher annual volumes of patients with inflammatory bowel disease (IBD) who undergo surgery have lower in-hospital mortality rates than hospitals with lower volumes of IBD patients, according to a new study by researchers at the Medical College of Wisconsin in Milwaukee.
The study also found a trend toward shorter post-operative hospital stays for patients who undergo surgery for Crohn's Disease, a form of IBD, at high-volume centers. Additionally, there was no increase in length of stay or hospitalization costs in higher-volume centers.
The study was presented at the Digestive Disease Week 2008 meeting by Ashwin Ananthakrishnan, M.D., M.P.H., clinical fellow of gastroenterology and hepatology at the Medical College and lead investigator of the study. It will be published in an upcoming issue of the American Journal of Gastroenterology.
IBD-related diseases are chronic gastrointestinal disorders and include Crohn's Disease and ulcerative colitis. These diseases often require hospitalization or surgical intervention leading to high health-care costs. The authors examined data from the 2004 Nationwide Inpatient Sample, which consists of data from 37 states and more than 1,000 participating hospitals. A total of 140,463 IBD-related hospitalizations were included in the study. In-hospital mortality, length of stay, frequency of surgery, and length of post-operative stay were the main outcomes measured in this study.
Hospitals that had one to 50 patients with IBD were categorized as low-volume centers. Hospitals with 51 to 150 patients with IBD were categorized as medium-volume, and more than 151 patients with IBD were considered high-volume.
High-volume centers experienced only one-third of the in-hospital mortality that low-volume centers experienced among patients who underwent surgery during hospitalization. According to Dr. Ananthakrishnan, "Patients who require surgery are usually patients with more severe diseases who are at higher risk for worse outcomes." However, there was no difference in mortality between high-volume and low-volume centers among patients who did not undergo surgery during the hospital stay.
Patients were also more likely to undergo surgery at high-volume centers. "This may be due to more referrals, but could also mean that these hospitals may be more sensitive to the need for early surgery than low-volume hospitals," explains Dr. Ananthakrishnan.
Patients at high-volume centers also had more complicated diseases than patients at low-volume centers. This is likely because such cases are more frequently treated at specialty centers and larger hospitals. "High-volume hospitals have no increase in length of stay or hospitalization costs despite caring for patients with more severe diseases," Dr. Ananthakrishnan added.
"The results of our study suggest a potential role for the establishment of designated centers of excellence for the care of complex hospitalized IBD patients. However, the first step is to further study what hospitals with good outcomes are doing differently and see how they can be applied to all hospitals," concluded Dr. Ananthakrishnan.
Other investigators for the study included Emily McGinley, epidemiologist in the department of population health; and David Binion, M.D., professor of medicine in the division of gastroenterology and hepatology at the Medical College.