CLSI M23-Ed4

Clinical and Laboratory Standards Institute document M23–Development of In Vitro Susceptibility Testing Criteria and Quality Control Parameters offers guidance for developing interpretive criteria and QC ranges for antimicrobial susceptibility tests against aerobic and anaerobic bacteria, and selected fungi performed by CLSI antimicrobial susceptibility testing standards. It describes the data used by the Subcommittees on Antimicrobial Susceptibility Testing and Antifungal Susceptibility Tests to establish these interpretive criteria and QC ranges for antimicrobial agents, including microbiological data, pharmacokinetic and pharmacodynamic characteristics, and clinical data. As antimicrobial agents are used in practice, additional experience accrued may be used to reassess interpretive criteria or QC ranges. Users of these guidelines should understand that susceptibility test results cannot predict clinical outcomes with absolute certainty. They should be used along with the best clinical judgment and laboratory support to draw the best conclusions to serve the patient.