Risk factors for mortality in Clostridium difficile infection in the general hospital population: a systematic review.

BACKGROUND: Clostridium difficile infection (CDI) is one of the most important healthcare-associated infections, causing considerable mortality. Numerous severity scores have been proposed to identify patients with CDI at risk of mortality, but a systematic review of the evidence upon which these are based has never been published. Such a review could permit future development of scores that better predict mortality. AIM: A systematic review of the published literature investigating clinically useful risk markers for mortality in CDI.
METHODS: We searched MEDLINE 1950 to present, Web of Science with conference proceedings 1899 to present and BIOSIS Citation Index 1969 to present using PubMed and Web of Knowledge. Potential risk markers that had been evaluated by at least four studies were extracted.
FINDINGS: Twenty-six studies, of 1617 initially identified, met inclusion criteria. The majority were retrospective cohort studies, mostly based in the USA. Older age, higher white blood cell count (WBC), higher creatinine level, lower albumin levels and, to a lesser extent, corticosteroid use were most frequently associated with mortality. Presence of fever, haemoglobin/haematocrit level, diarrhoea severity, presence of renal disease, diabetes, cancer, or nasogastric tube use did not appear to be associated with mortality.
CONCLUSION: Our results support the use of age, WBC, serum creatinine, serum albumin level and possibly pre-existing corticosteroid use as potentially useful risk markers for mortality in CDI. Our results do not support the use of fever, haemoglobin/haematocrit, diarrhoea severity and several comorbidities as useful risk markers, raising questions about their inclusion in CDI severity scores.