Spectrum scores: Toward a better definition of de-escalation.

Spectrum scores measure antimicrobial utilization while also quantifying the spectrum of activity. Accordingly, changes in spectrum score can be used to identify antimicrobial de-escalation. We show that spectrum-score-based de-escalation has a 95.7% positive percentage agreement and 81.6% negative percentage agreement versus de-escalation defined as stopping either antistaphylococcal or antipseudomonal agents.