A waterfall of susceptibility results: impact of microbiology testing cascade for MDROs.

Cascade reporting is an antimicrobial stewardship strategy which selectively reports broad-spectrum antibiotic susceptibility when narrower-spectrum agents are resistant. Three regional laboratories, which provide microbiology services for HCA Healthcare hospitals in Florida, implemented a standardized antibiotic testing cascade for multi-drug resistant organisms. This study evaluated the impact of the testing cascade on time to susceptibility results for carbapenem-resistant Gram-negative organisms.