Rising economic impact of Clostridium difficile - Associated disease in adult hospitalized patient population

Background. Clostridium difficile-associated disease (CDAD) is responsible for increased morbidity and a substantial economic burden. Incidences of CDAD, including those with a severe course of illness, have been increasing rapidly. Objective. To evaluate the excess mortality, increased length of stay (LOS) in the hospital, and additional costs associated with CDAD. Design. A retrospective matched cohort study. Patients. Adult patients admitted to a large tertiary care hospital between January 2000 and October 2005. Methods. Adult patients were tested with a C. difficile laboratory assay at admission or 72 hours after admission. Infected patients had 1 or more positive assay results and were individually matched to 1 uninfected patient who had negative assay results, by exposure time, age, ward, and at least 2 measurements for comorbidity and severity of illness. Results. The incidence rate of CDAD among adult patients increased from 0.57 cases per 1,000 patient-days at risk before 2004 to 0.88 cases per 1,000 patient-days at risk after 2004 (P < .001). The 630 infected patients had a mortality rate of 11.9%; the 630 uninfected patients had a mortality rate of 15.1% (P = .02). After adjustment in the multivariate analysis, we found that the LOS for infected patients was 4 days longer than that for uninfected patients (P < .001). If CDAD occurred after 2004, the additional LOS increased to 5.5 days. The direct cost associated with CDAD was $306 per case; after year 2004, it increased to $6,326 per case. Conclusions. There may be no excess mortality among patients with CDAD, compared with patients without it, but the economic burden of CDAD is increasing. By 2004, CDAD-associated medical expenditures approached $1,000,000 per year at our institution alone.