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) (>= 145 IBD admissions annually and assessed their impact on mortality. Results: Over 7 years the proportion of patients admitted to HIVACs increased front 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 file 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.