Timing and Magnitude of CDI Risk Associated with Antibiotic Exposures.

Abbreviations: AIC, Akaike's Information Criterion; CDI, Clostridium difficile infection; CI, confidence interval; d, days; IR, incidence rate; IRR, incidence rate ratio.aIncidence rate, per 10,000 patient-days.bThe difference in AIC relative to the reference model (current antibiotic use): negative numbers denote an improvement in fit. Δ AIC cAdjusted for time since hospital admission, age, sex, number of previous hospital admissions, infection pressure, and current or prior ICU admission.Timing and Magnitude of CDI Risk Associated with Antibiotic Exposures.