A, Model output for adult encounters. B, Model output for pediatric and neonatal encounters. Each data point represents a unique model built based on location, feasibility tier of variables used, antimicrobial group, and adult or pediatric populations. The closer the AUC value is to 1, the better the model was at classifying whether antimicrobials were administered. Some location strata in the analysis of pediatric encounters were too small to fit a model. In these scenarios, only estimates for the “all locations” category were reported. Antimicrobial groups and agents are listed in eTable 1 in the Supplement. AUC indicates area under the curve; BL, beta-lactam; CDI, Clostridioides difficile infection risk agents; CO, community onset; and ICU, intensive care unit.