Data are limited on the attributable outcomes of Clostridium diffi cile-associated disease (CDAD), particularly in CDAD-endemic settings. We conducted a retrospective cohort study of nonsurgical inpatients admitted for >48 hours in 2003 (N = 18,050). The adjusted hazard ratios for readmission (hazard ratio 2.19, 95% confi dence interval [CI] 1.87-2.55) and deaths within 180 days (hazard ratio 1.23, 95% CI 1.03-1.46) were signifi cantly different among CDAD case-patients and noncase patients. In a propensity score matched-pairs analysis that used a nested subset of the cohort (N = 706), attributable length of stay attributable to CDAD was 2.8 days, attributable readmission at 180 days was 19.3%, and attributable death at 180 days was 5.7%. CDAD patients were signifi cantly more likely than controls to be discharged to a long-term-care facility or outside hospital. Even in a nonoutbreak setting, CDAD had a statistically signifi cant negative impact on patient illness and death, and the impact of CDAD persisted beyond hospital discharge.C lostridium diffi cile-associated disease (CDAD) is an increasingly common cause of hospital-associated diarrhea (1,2). The emerging NAP1 strain of C. diffi cile has been associated with numerous outbreaks and appears to be more virulent than other endemic and epidemic C. diffi cile strains (3-9). Despite the increasing importance of this pathogen, few data exist on outcomes attributable to CDAD (10-14). The attributable mortality for CDAD has recently been estimated at 6.9% and 16.7% (9,12). However, these studies were performed during CDAD outbreaks caused by the NAP1 strain. Published estimates of CDAD-attributable deaths in disease-endemic settings are much lower (1.2%-1.5%) (10,13). Kyne et al. did not fi nd endemic CDAD to be an independent predictor of death within 1 year of CDAD, but that study was relatively small (47 CDAD cases) (11). Thus, additional data with larger sample sizes are needed to determine outcomes associated with CDAD in nonoutbreak settings. With a large cohort of CDAD patients at a tertiary-care center, we evaluated CDAD outcomes including length of stay, hospital discharge status, time-to-readmission, and deaths in a CDADendemic setting.
MethodsThis study was conducted at Barnes-Jewish Hospital (BJH), a 1,250-bed, tertiary-care academic hospital in St. Louis, Missouri. Eligibility was limited to nonsurgical patients admitted for >48 hours from January 1 through December 31, 2003. Nonsurgical patients were defi ned as those without operating room costs. Surgical patients were excluded because of their heterogeneity. Specifi cally, risk factors for length of stay, readmission to the hospital, and death were different in this population compared with other hospitalized patients. Data were primarily collected from the hospital's Medical Informatics database. The database was queried to collect patient demographics; admission and discharge dates; International Classifi cation of Diseases, 9th edition, Clinical Modifi cation (ICD-9-CM), diagnosis and procedur...