Association between Antibiotic Use and Hospital-Onset Clostridioidesdifficile Infection in U.S. Acute Care Hospitals, 2006-2012: an Ecologic Analysis.

Background. Unnecessary antibiotic use (AU) contributes to increased rates of Clostridioides difficile infection (CDI). The impact of antibiotic restriction on hospital-onset CDI (HO-CDI) has not been assessed in a large group of US acute care hospitals (ACHs). Methods. We examined cross-sectional and temporal associations between rates of hospital-level AU and HO-CDI using data from 549 ACHs. HO-CDI was defined as a discharge with a secondary International Classification of Diseases, Ninth Revision, Clinical Modification code for CDI (008.45), and treatment with metronidazole or oral vancomycin > 3 days after admission. Analyses were performed using multivariable generalized estimating equation models adjusting for patient and hospital characteristics. Results. During 2006-2012, the unadjusted annual rates of HO-CDI and total AU were 7.3 per 10 000 patient-days (PD) (95% confidence interval [CI], 7.1-7.5) and 811 days of therapy (DOT)/1000 PD (95% CI, 803-820), respectively. In the cross-sectional analysis, for every 50 DOT/1000 PD increase in total AU, there was a 4.4% increase in HO-CDI. For every 10 DOT/1000 PD increase in use of third- and fourth-generation cephalosporins or carbapenems, there was a 2.1% and 2.9% increase in HO-CDI, respectively. In the time-series analysis, the 6 ACHs with a >= 30% decrease in total AU had a 33% decrease in HO-CDI (rate ratio, 0.67 [95% CI, .47-.96]); ACHs with a >= 20% decrease in fluoroquinolone or third- and fourth-generation cephalosporin use had a corresponding decrease in HO-CDI of 8% and 13%, respectively. Conclusions. At an ecologic level, reductions in total AU, use of fluoroquinolones, and use of third- and fourth-generation cephalosporins were each associated with decreased HO-CDI rates.