Association Between High-Risk Medication Usage and Healthcare Facility-Onset C. difficile Infection

OBJECTIVE National hospital performance measures for C. difficile infection (CD) are available; comparing antibacterial use among performance levels can aid in identifying effective antimicrobial stewardship strategies to reduce CDI rates. DESIGN Hospital-level, cross-sectional analysis. METHODS Hospital characteristics (ie, demographics, medications, patient mix) were obtained for 77 hospitals for 2013. Hospitals were assigned 1 of 3 levels of a CDI standardized infection ratio (SIR): 'Worse than,' 'Better than,' or 'No different than' a national benchmark. Analyses compared medication use (total and broad-spectrum antibacterials) for 3 metrics: days of therapy per 1,000 patient days; length of therapy; and proportion of patients receiving a medication across SIR levels. A multivariate, ordered-probit regression identified characteristics associated with SIR categories. RESULTS Regarding total average antimicrobial use per patient, there was a significant difference detected in mean length of therapy: 'No different' hospitals having the longest (4.93 days) versus 'Worse' (4.78 days) and 'Better' (4.43 days) (P<.01). 'Better' hospitals used fewer total antibacterials (693 days of therapy per 1,000 patient days) versus 'No different' (776 days) versus 'Worse' (777 days) (P<.05). The 'Better' hospitals used broad-spectrum antibacterials for a shorter average length of therapy (4.03 days) versus 'No different' (4.51 days) versus 'Worse' (4.38 days) (P<.05). 'Better' hospitals used fewer broad-spectrum antibacterials (310 days of therapy per 1,000 patient days) versus 'No different' (364 days) versus 'Worse' (349 days) (P<.05). Multivariate analysis revealed that the proportion of elderly patients and chemotherapy days of therapy per 1,000 patient days was significantly negatively associated with the SIR. CONCLUSIONS These findings have potential implications regarding the need to fully account for hospital patient mix when carrying out inter-hospital comparisons of CDI rates. Infect Control Hosp Epidemiol 2016;37:909-915.