Introduction: Clostridium difficile infection (CDI) related severity as defined by Infectious Diseases Society of America (IDSA) is based on laboratory or clinical parameters at the time of presentation. CDI related sepsis could lead to worsening of otherwise stable underlying comorbid conditions and hence may escalate mortality risk. Charlson Comorbidity Index (CCI), which assesses patient’s underlying co-morbid illness, may help in prognosis estimation and prediction of clinical outcomes. In our study, we intend to analyze the CCI as a tool to predict poor outcomes across all CDI severities.
Methods: We conducted a 10 years, retrospective observation study on patients with CDI from April 2008 to November 2018. Demographic, clinical and laboratory was abstracted from our Electronic Health Record. Based on IDSA severity all patients were divided into non-severe, severe and fulminant disease. The primary outcome was defined as death during the same hospital admission as CDI. The CCI index was calculated based on chart review. IDSA severity and Charlson’s comorbidity index were included as independent variables in conducting multivariate analysis. The cut-off point for Charlson’s comorbidity index was calculated based on Youden’s index. Estimated marginal odds were derived using the binary logistic regression model to make predictions about the included parameters.
Results: There were 1470 hospitalized patients with CDI and majority of patients had non-severe presentation (44%, 647), followed by severe (35%, 527) and fulminant disease (21%, 296). The overall mortality rate was 14.9% (219). The CCI cut-off of 5 was best at predicting the mortality in patients with CDI with a sensitivity of 70% and specificity of 53%. The impact of CCI >5 on the CDI related morality could be seen across all CDI severity groups, specifically in the group with non-severe presentation. In patient with non-severe CDI, the patients with CCI > 5 had 3.67 times higher odds of mortality as comparted to patient with CCI < 5 (OR = 3.67, p= < 0.001). In patients with severe and fulminant infection, the odds of mortality were 2.22 and 2.31, respectively (P < 0.05 for both comparisons).
Discussion: CCI > 5 affects the mortality in patients with CDI across all severity. Exacerbation of co-morbid condition due to CDI is likely explanation. Inclusion of CCI in CDI severity, in addition to IDSA criteria, may assist in improving overall prognosis of patients.
