Nationwide patterns of hospitalizations to centers with high volume of admissions for inflammatory bowel disease and their impact on mortality.

BACKGROUND: We sought to determine patterns of hospitalizations for inflammatory bowel disease (IBD) to centers that regularly admit high volumes of IBD patients and whether they impacted health outcomes.
METHODS: We queried US hospital discharges in the Nationwide Inpatient Sample to identify admissions with a primary diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) between 1998 and 2004. We determined patterns and predictors of hospitalization at high IBD volume admission centers (HIVACs) (>or=145 IBD admissions annually) and assessed their impact on mortality.
RESULTS: Over 7 years the proportion of patients admitted to HIVACs increased from 2.3% to 14.8%. IBD patients were less likely to be admitted to an HIVAC if they were insured by Medicare (odds ratio [OR] 0.74; 95% confidence interval [CI]: 0.65-0.83) or Medicaid (OR 0.71; 95% CI: 0.60-0.84), or were uninsured (OR 0.42; 95% CI: 0.30-0.58) compared with those privately insured. Neighborhood income above the national median favored admission to an HIVAC (OR 1.99; 95% CI: 1.46-2.71). In-hospital mortality was lower among HIVACs compared to non-HIVACs (3.5/1000 versus 7.2/1000, P < 0.0001) and was persistent after adjustment for surgery status, age, comorbidity, and health insurance (OR 0.65; 95% CI: 0.49-0.87). When stratified by diagnosis, mortality was reduced at HIVACs among CD (OR 0.58; 95% CI: 0.37-0.90) but not UC admissions.
CONCLUSIONS: There is a rising trend in hospitalizations for IBD at HIVACs, which confers mortality benefit for those with CD. Prospective studies are warranted to further explore the impact of these high-volume centers on IBD health outcomes.