Investigation of critical care unit utilization and mortality in patients infected with Clostridium difficile

Background: A nationwide increase in the rate and severity of Clostridium difficile-associated disease may reflect infection with a virulent strain characterized by polymerase chain reaction as ribotype 027 (NAP1/B1). Hypothesis: The high prevalence of ribotype 027 at our institution would allow investigation of the risk of mortality and admission to the intensive care unit (ICU) associated with C difficile infection. Methods: In a retrospective cohort study, we identified 108 patients with positive enzyme-linked immunosorbant assay tests for C difficile toxins over a 6-month period and compared them to 108 patients who were suspected to have C difficile but with negative toxin assays. Proportions of all-cause mortality and ICU admission were compared using chi(2), and odds ratios (ORs) were estimated using logistic regression to adjust for potential confounders. Mean log lengths of stay were compared using t test. Results: Comparing patients with C difficile to those without, mortality (20% vs 8%) and ICU admission (32% vs 17%) were significantly higher (P= .02 for both), whereas log length of stay was not (P = .29). Adjusting for potential confounders, the OR for mortality was 6.8 (95% confidence interval, 1.8-25.4; P = .01), whereas for ICU admission, the association was no longer observed (OR, 1.0; 95% confidence interval, 0.4-2.5; P = .97). Conclusion: C difficile infection was associated with increased all-cause mortality. An observed association with ICU admission and C difficile infection was identified through univariate analysis but was not significant in multivariate analysis. Although we did not strain-type isolates for patients infected with C difficile, the institutional prevalence of ribotype 027 C difficile infection was known to be high. These results document a strong association between ribotype 027 C difficile infection and mortality and underscore the need to identify effective C difficile preventive strategies. (C) 2010 Elsevier Inc. All rights reserved.