Antimicrobial Stewardship May Reduce Clostridium difficile Infection in Long-Term Care Settings

Antibiotic use and importation of infection from acute care facilities account for three-quarters of the regional variation in the incidence of Clostridium difficile (C difficile) at Veterans Health Administration long-term care facilities, according to a study in Annals of Internal Medicine (published online April 19, 2016, doi:10.7326/M15-1754).

The study was funded by the US Department of Veterans Affairs and the Centers for Disease Control and Prevention. Researchers, led by Kevin A Brown, PhD (Public Health Ontario, Toronto), investigated individual and regional factors affecting C difficile incidence in long-term care. They analyzed patient factors such as age, number of comorbid conditions, and antibiotic exposure, as well as regional factors including importation of cases of acute care infection per 10,000 resident days (RD) and antibiotic use per 1000 RD.

The study identified 6012 cases of C difficile infection across 86 Veterans Health Administration regions between 2006 and 2012. The overall incidence was 3.7 cases per 10,000 RD. Across regions, incidence of C difficile, antibiotic use, and importation of acute care C difficile varied considerably.

Specifically, C difficile incidence ranged from 0.6 cases to 31 cases per 10,000 RD; antibiotic use ranged from 61 days to 370.2 days with therapy per 1000 RD; and importation ranged from 2.9 cases to 341.3 cases per 10,000 RD. Together, antibiotic use and importation accounted for 75% of the regional variation in C difficile incidence (R2, 0.75). Multilevel analyses showed that regional factors affected risk together with individual-level exposures (relative risk of regional antibiotic use, 1.36 per doubling [95% CI, 1.15 to 1.60]; relative risk of importation, 1.23 per doubling [CI, 1.14 to 1.33]).

“Only 25% of the variation in regional C difficile incidence in long-term care remained unexplained after importation from acute care facilities and antibiotic use were accounted for,” researchers wrote, “which suggests that improved infection control and antimicrobial stewardship may help reduce the incidence of C difficile in long-term care settings.” 

Researchers were careful to note that the case identification was based on laboratory criteria, and admission of residents with recent C difficile infection from non-Veterans Health Administration acute care sources was not considered. —Amanda Del Signore