Trends in Clostridioides difficile prevalence, mortality, severity, and age composition during 2003-2014, the national inpatient sample database in the US

Background: Clostridioides difficile (formerly known as Clostridium difficile) infection (CDI) is one of the most prevalent healthcare-associated infections in the United States (US). In the early 2000s, CDI emerged as a great threat with increasing prevalence, mortality, and severity, especially in advanced age. We investigated the US national trends in in-hospital CDI prevalence, mortality, severity, and age composition from 2003 to 2014.

Methods: We identified the patients with CDI using the national inpatient sample data from 2003 to 2014. We performed Poisson regression model and Kendall's tau-b correlation test for our analyses.

Results: Adjusted overall CDI prevalence did not significantly change during 2003-2014. In-hospital mortality of overall CDI did not significantly change during 2003-2008, then significantly decreased during 2008-2014. Severity of overall CDI significantly increased during 2003-2008, then decreased during 2008-2014. The proportions of patients with age $\ge$ 65 years decreased in CDI prevalence, mortality, and severity during 2003-2014.

Conclusions: Compared to the earlier years 2003-2008, overall CDI outcome improved in the later years 2008-2014. Younger patients increasingly contributed to CDI prevalence, mortality, and severity during 2003-2014. More studies to understand underlying driving forces of changes in CDI trends are warranted to mitigate CDI.