Table 4.

Direct antimicrobial stewardship metrics.

ASP Metrics	Description
Antimicrobial use of broad-spectrum agents: Antipseudomonal beta-lactams Carbapenems Anti-MRSA agents Anti-VRE agents	Most direct measure of ASP performance Evaluates effectiveness of ASP interventions (e.g., syndrome-specific, prospective audit and feedback, de-escalation of therapy) Measures both empirical and definitive therapy Adjustments by quantity (facility size, patient population, or microbiological burden) and quality (appropriateness of therapy) at each healthcare facility are possible
Antimicrobial resistance of predominantly hospital-onset bacteria: Pseudomonas aeruginosa Acinetobacter baumannii	Antimicrobial resistance of hospital-onset bacteria is associated with use of broad-spectrum antimicrobials at each institution Antimicrobial resistance may also be influenced by referrals, especially at tertiary care centers Patient-to-patient transmission of MDR bacteria may be reduced by effective infection prevention and control methods
Incidence rate of CRE	Excessive use of carbapenems and other broad-spectrum antimicrobials increases risk of CRE infections or colonization CRE rates may be influenced by transfers from other hospitals or skilled nursing facilities Infection prevention and control programs are essential for reducing transmission of CRE in healthcare facilities

Note: ASP: antimicrobial stewardship programs; MRSA: methicillin-resistant Staphylococcus aureus; VRE: vancomycin-resistant Enterococcus species; MDR: multi-drug resistant; CRE: carbapenem-resistant Enterobacteriaceae.