Objective: To determine, among patients with Clostridium difficile infection (CDI) at hospital admission, the impact of concurrent use of systemic, non-CDI-related antimicrobials on clinical outcomes and the risk factors associated with unnecessary antimicrobial prescribing.
Design: Retrospective cohort study.
Setting: University-affiliated community hospital.
Methods: We reviewed computerized medical records for all patients with CDI at hospital admission during a 24-month period (January 1, 2008, through December 31, 2009). Colectomy, discharge to hospice, and in-hospital mortality were considered to be adverse outcomes. Antimicrobial use was considered unnecessary in the absence of physical signs and laboratory or radiological findings suggestive of an infection other than CDI or in the absence of antimicrobial activity against the organism(s) recovered from clinical cultures.
Results: Among the 94 patients with CDI at hospital admission, 62% received at least one non-CDI-related antimicrobial during their hospitalization for CDI. Severe complicated CDI (odds ratio [OR], 7.1 [95% confidence interval {CI}, 1.8-28.5]; [Formula: see text]), duration of non-CDI-related antimicrobial exposure (OR, 1.2 [95% CI, 1.03-1.36]; [Formula: see text]), and age (OR, 1.1 [95% CI, 1.0-1.1]; [Formula: see text]) were independent risk factors for adverse clinical outcomes. One-third of the patients received unnecessary antimicrobial therapy. Sepsis at hospital admission (OR, 5.3 [95% CI, 1.8-15.8]; [Formula: see text]) and clinical suspicion of urinary tract infection (OR, 9.7 [95% CI, 2.9-32.3]; [Formula: see text]) were independently associated with unnecessary antimicrobial prescriptions.
Conclusions: Empirical use of non-CDI-related antimicrobials was common. Prolonged exposure to non-CDI-related antimicrobials was associated with adverse clinical outcomes, including increased in-hospital mortality. Minimizing non-CDI-related antimicrobial exposure in patients with CDI seems warranted.