Risk factors for Clostridium difficile toxin-positive nosocomial diarrhoea.

Data were retrieved from the records of all patients from whom stool was sent for Clostridium difficile toxin testing during the year 2001. Toxin-positive and -negative patients were compared by bivariate analysis and regression models. Eight hundred samples from 610 patients were sent for C. difficile toxin testing. Charts of 535 patients (88%) were available for analysis. Of those, 17% had a positive toxin test whilst 83% had a negative toxin test. There was no difference in the number of daily bowel movements between the two groups. Toxin-positive patients were older (P<0.0001), more often came from nursing homes (P<0.05), had higher leukocyte counts (P<0.001), higher blood urea nitrogen (P<0.01), lower serum albumin (P<0.01) and more often received diuretics (P<0.01) and clindamycin (P<0.05). Logistic regression analysis showed that previous antibiotic-associated diarrhoea was the most significant risk factor for toxin-positive diarrhoea (P<0.001), followed by clindamycin treatment (P<0.005), diuretics (P<0.005) and older age (P<0.05). Another logistic model showed the contribution of macrolides (P<0.05) to the development of hospital-acquired diarrhoea.