Predictive Value of Direct Disk Diffusion Testing from Positive Blood Cultures in a Children’s Hospital and Its Utility in Antimicrobial Stewardship

with ceftriaxone. NPVs of dDD were variable and frequently lower than the PPV. Very major errors and major errors occurred in 31/5,454 (0.6%) and 231/5,454 (4.2%) organism-antibiotic combinations, respectively. Antibiotics were narrowed in 30% of cases after a dDD result and a further 25% of cases after AST result. dDD is highly predictive of susceptibility for many common organism-antibiotic combinations and provides actionable information one day earlier than standard susceptibility approaches. dDD has the potential to facilitate earlier deescalation to narrow-spectrum antibiotic treatment.