Mortality and attributable mortality of C.difficile infection in critical ill patients

Abstract number: P1464

Leitner J., Schmid D., Kuo H.W., Allerberger F., Tesik P., Michl V., Wenisch C.

Objectives: A prospective hospital-based cohort study was performed between November 2008 and August 2009 to measure the attributable mortality of C. difficile infection (CDI) in patients with CDI compared with non-diarrhoea patients admitted at the intensive care unit (ICU) with equal comorbidity score.

Methods: 90 CDI patients and 180 ICU non diarrhea patients were included. Death risk ratio and attributable risk of death (i.e. excess mortality) were used to measure the relative and absolute effect of CDI on the risk of pre-discharge mortality within the two comorbidity-severity categories low and moderate-severe comorbidity using the Charlson Comorbidity score. Death risk ratio was calculated by death risk in the CDI-group (exposed group) / death risk in the ICU-group (unexposed group) and the attributable risk of death (attributable mortality) was calculated death riske – death risku. The attributable risk percent, AR% (mortality fraction) was calculated by AR%= (death riske – death risku) / death riske X 100. Death risks were compared by using c2 test or the Fisher's exact test. The survival time between the CDI-patient-group and ICU-patient group within the two comorbidity-severity categories was analysed by using Kaplan–Meier survival analysis. For the CDI-patient group day zero corresponded to the date of disease onset, and for the IC-patient group day zero corresponded to the day of ICU admission. Study subjects with a follow up period of at least 30 days were included in this survival analysis. A total of 141 ICU-patients and all the 90 CDI patients remained for this analysis.

Results: Table 1 shows the risk of death in low compared to moderate & severe comorbidity in CDI and ICU non diarrhea patients.

Within 30 days CDI patients with low comorbitiy showed higher survival rate than the ICU patient-group (p < 0.001). No significant difference was observed between survival rates of the CDI patients and ICU patients in the moderate/severe comorbidity category.

Conclusion:C. difficile infection does neither result in increased mortality in patients with low nor with moderate/severe Charlson comorbidity score.

Table 1. Effect of CDI on the mortality risk; CDI-patient group compared with the ICU-patient group by comorbidity severity categories low and moderate/severe

Comorbidity severityRisk of death in:RR (95% CI)Excess mortalityMortality fraction
Sub-cohort I: Low comorbidity4.2% (2/48)39.8% (53/133)0.1 (0.03–0.41)n.a.n.a.
Sub-cohort II: moderate & severe comorbidity28.6% (12/42)21.3% (10/47)1.34 (0.65–2.78)7.3%25.5%

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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