Rising Incidence of Intestinal Infections in Inflammatory Bowel Disease: A Nationwide Analysis

Background: Intestinal infections are common in patients with inflammatory bowel disease (IBD) and may mimic IBD flares. In this study, we estimate the changing incidence of intestinal infections among IBD hospitalizations and assess the impact of intestinal infections on key hospitalization metrics. Methods: The National Inpatient Sample (NIS) was analyzed for hospitalizations from IBD between 1998 and 2014. Intestinal infections were identified using ICD-9-CM codes, and incidence for each infection was calculated for Crohn's disease (CD) and ulcerative colitis (UC). Linear and logistic regression analyses were used to assess the effects of intestinal infections on hospitalization duration, charges, and mortality. Results: There were 4,030,620 hospitalizations for IBD between 1998 and 2014. The annual incidence of intestinal infections rose from 26.2 to 70.6 infections per 1000 IBD hospitalizations (P-trend < 0.01). A main driver of this rising incidence was Clostridium difficile infections, which increased from 7.8 to 32.1 per 1000 CD hospitalizations and from 23.0 to 84.7 per 1000 UC hospitalizations (P-trend < 0.01). The incidence of other intestinal infections increased from 10.2 to 15.3 per 1000 CD hospitalizations and 16.5 to 25.3 per 1000 UC hospitalizations. Intestinal infections and particularly C. difficile infections were associated with longer hospitalizations, greater hospital charges, and greater all-cause mortality. Conclusions: The incidence of intestinal infections among hospitalized IBD patients has increased over the past 15 years, primarily driven by C. difficile infections. Intestinal infections are associated with length of stay, hospital charges, and all-cause mortality. More aggressive measures for prevention of C. difficile infections are needed.