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.