1098 — The Determinants of C. difficile Infection in Long-Term Care Facilities: A Portrait of Patient- and Facility-Level Factors across 90 VA Care Regions

Brown KA, Salt Lake VAMC; Jones M, Salt Lake VAMC; Adler F, University of Utah; Leecaster M, University of Utah; Nechodom K, University of Utah; Stevens V, University of Utah; Samore M, Salt Lake VAMC; Mayer J, University of Utah;

Objectives:
Clostridium difficile infection (CDI) is an infectious diarrheal disease that is associated with antibiotic and healthcare exposures. Although individual-level risk factors have been extensively studied, the facility-level factors that drive CDI have not. Our objective was to study the determinants of CDI incidence across long term care (LTC) facilities, with a specific interest in the role importation of infectious patients from acute care (AC) facilities.

Methods:
We conducted a retrospective cohort study of CDI from 2006 through 2012 across Veterans Affairs local healthcare systems (HCS) where both AC and LTC patient censuses were above an average of 10 patients per day. Our outcome was LTC-onset C. difficile lab-identified event, defined as a case with onset ? 3 days after admission occurring at least 8 weeks from a previous positive test. The facility-level exposures we studied included: C. difficile importation (prevalence of AC facility-onset CDI cases per 10,000 resident-days), facility-level antibiotic use (days of therapy per 1,000 resident-days), mean resident age, and size (average daily census).

Results:
We identified 90 local HCS that met our inclusion criteria. The incidence of C. difficile infection in LTC facilities was 3.6 per 10,000 patient-days. In bivariate weighted linear regression analyses, the most important predictors of facility CDI incidence were importation (R2 = 0.63, p < 0.001) and antibiotic prescribing (R2 = 0.58, p < 0.001). Time-series analyses revealed that increases in C. difficile case importation from AC facilities preceded increases in CDI rates for a period of up to 8 weeks. Multi-level analyses revealed that C. difficile importation and facility-level antibiotic use acted independently of resident age, direct antibiotic exposure and direct proton pump inhibitor use.

Implications:
This is the first study showing that importation of C. difficile cases from AC facilities and facility-level antibiotic use are principal drivers of CDI in LTC facilities.

Impacts:
This research points to the need to: 1) control C. difficile infection at source AC facilities, 2) bolster infection control programs in LTC facilities where importation is high, and 3) monitor and reduce facility-level antibiotic use in partnership with local antimicrobial stewardship programs.