Trends in admissions, outcomes and financial burden of c. difficile infection related hospitalizations among inflammatory bowel disease patients: a nationwide analysis

Abstract INTRODUCTION Inflammatory bowel disease (IBD) patients with colonic involvement are known to have microbiome changes which may increase their risk of C. difficile infection (CDI). We conducted an analysis to describe the implications of CDI on hospitalized IBD patients. METHODS We used the National Inpatient Sample database from 2007 through 2018, to identify patients admitted with primary or secondary diagnosis of IBD using the ICD-9 or ICD-10 codes. We identified CDI as well as colectomy using diagnostic codes. We identified trends in nationwide estimates for annual admissions, age at admission, length of stay (LOS), in-patient mortality, Elixhauser comorbidity index and total hospital charge (adjusted for inflation). We used the Cochran-Armitage test for trend significance. RESULTS Between 2007 and 2018, there were an estimated total of 3,728,348 admissions with IBD, of which 161,744 patients had CDI (4.3%). Median age at admission was 52 years, with 56.7% females. There was a rising trend of CDI among IBD patients, from 2.9% in 2007 to a peak of 5.4% in 2015 with a decline towards the end of study period at 4.4% in 2018. Mean score for Elixhauser comorbidity index increased from 4.6 to 7.4 (p-trend <0.05) for non-CDI subgroup and from 9.9 to 11.4 (p-trend <0.05) for CDI subgroup during the study period. The median LOS was 4 days for patients without CDI vs 6 days with CDI. Trend in LOS was stable for patients without CDI but decreased from 8 days to 5 days over the 12-year study period for patients with CDI (p-trend <0.05). Overall, among patients with IBD, the risk of colectomy was 5.3%. Risk was higher in CDI subgroup (7.3% vs 5.2%, RR 1.41, 95% CI 1.39 - 1.44). The overall mortality among IBD patients was 1.6% with no significant trend observed over time. All cause in-hospital mortality was significantly higher among patients with concomitant CDI (6.8%) vs without CDI (1.4%) (RR 4.99, 95% CI 4.89 - 5.10). Within CDI subgroup, there was a trend of decrease in mortality from 7-11% in the beginning of the study, to about 3-3.5% towards the end of the study period (p-trend <0.05). After adjusting for inflation, there was a significant increase in charges among both subgroups: increased from $28,575 in 2007 to $68,614 in 2018 (p-trend <0.005) for non-CDI subgroup and from $57,987 in 2007 to $95,799 in 2018 (p-trend <0.005) for CDI subgroup. Overall charges were significantly higher for CDI subgroup. CONCLUSION The incidence of CDI in IBD patients increased over the study period with stability towards the latter half. Hospitalized IBD patients with concomitant CDI have a higher comorbidity index, a longer length of stay, a higher risk of colectomy and an increased risk of mortality when compared to those without CDI. Total hospitalization charges are also significantly higher with CDI subgroup and have been increasing overtime.