Maintaining Current Breakpoints for Antimicrobial Susceptibility Testing

Effective January 1, 2024

Essential to patient care, antimicrobial susceptibility testing (AST) manages therapies for many types of infectious diseases. The most critical step of this process involves the interpretation of the results through the assignment of clinical breakpoints, which correlate with the probability of clinical outcomes. Implementation of revised breakpoints directly impacts diagnostic stewardship, patient management, and public health efforts, leading to improved patient care.

In the September 2021 checklist edition, the College of American Pathologists (CAP) added Microbiology checklist requirement MIC.11385 (Current Antimicrobial Susceptibility Test Interpretation Criteria) with an effective date of January 1, 2024, to allow laboratories time to understand and implement changes needed for compliance. From that point on, laboratories will be required to use current breakpoints to interpret antimicrobial minimum inhibitory concentration and disk diffusion test results.

Be Prepared with These Resources from the CAP

To ensure our accredited laboratories are prepared for this new requirement, the CAP has the following resources available to help guide you through the transition.

Antimicrobial Susceptibility Testing: Understanding New CAP Requirements Module

This learning activity, presented by Romney Humphries, PhD D(ABMM), FAAM, FIDSA, provides expert insight into microbiology breakpoints, links to helpful resources, and knowledge checks to ensure understanding of the new requirements.

Complete the Activity

Breakpoint FAQs MIC.11380 and MIC.11385 Document

This document answers commonly asked question for updating breakpoints.

Review the FAQs

Updating Breakpoints in Antimicrobial Susceptibility Testing

Learn more about clinical breakpoints and the CAP's new checklist requirements in this American Society for Microbiology article.

Read the Article

2023 Breakpoints in Use Toolkit

This comprehensive list of resources, resulting from a collaboration of the CAP, Clinical and Laboratory Standards Institute, Association of Public Health Laboratories, American Society for Microbiology, and Centers for Disease Control and Prevention, offers information and guidance on the requirements as well as the rationale behind breakpoint updates, regulatory requirements for updating breakpoints, and detailed instructions for performing an AST breakpoint validation or verification. Find the toolkit under Microbiology.

Open the Toolkit