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

Abstract 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 χ2 , 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.