CASE-CONTROLLED REVIEW OF CLOSTRIDIUM-DIFFICILE-ASSOCIATED DIARRHEA IN SOUTHERN TASMANIA

Aim: While the incidence of Clostridium difficile-associated diarrhoea (CDAD) has increased sharply over the last 15 years, its risk factors are still not well defined. The aim of this study was to review cases of CDAD at the major teaching hospital in Tasmania, Australia, to ide ntify risk factors for CDAD and their association with prognosis. Meth ods: A retrospective review of the medical records of adult patients a dmitted to the hospital between January 1994 and December 1996 was per formed. Sixty-four patients who developed CDAD prior to or during thei r admission, and an additional 120 diarrhoea-free patients (the contro l group) were studied. An extensive range of demographic and clinical variables were recorded, and the differences between the control group and patients with CDAD were evaluated. Results: The CDAD patients had a median age of 66 years (range 22-95 years), with females accounting for 52% of cases. There were no significant demographic differences f rom the control group. Identifiable risk factors for developing CDAD w ere severe underlying disease, renal impairment, exposure to antibioti cs or antineoplastic agents, and the use of total parenteral nutrition or nasogastric feeding. Cephalosporins were the most frequently used antibiotics in both CDAD and control patients, with cefotaxime being t he only antibiotic which was identified as being significantly associa ted with an increased risk of CDAD. The median length of diarrhoea epi sodes was 9 days (range 1-60 days). The mortality rate was 17.2%, and factors associated with a poor prognosis were older age, severe underl ying disease, renal impairment and failure to treat with metronidazole or vancomycin. Delay in starting specific treatment and use of codein e were related to prolonged CDAD. Conclusion: CDAD is a growing contri butor to hospital morbidity and costs. Severely ill patients with comp romised immune function are particularly susceptible, with antibiotic use being a major risk factor. Prompt diagnosis and initiation of trea tment are important factors in the improvement of prognosis.