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

Abstract

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. 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. 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. 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.