CQMCommonQDM Library

The CQMCommonQDM Library (formerly known as the Global Common Library) is a shared, standardized library of Clinical Quality Language (CQL) functions and expressions built on the Quality Data Model (QDM). It provides reusable logic that can be referenced by multiple electronic clinical quality measures (eCQMs), eliminating the need for each measure to independently implement common functionality.

The library helps eCQM developers to:

• Reuse common logic across multiple measures
• Promote consistency and alignment in measure specifications
• Reduce duplication of code and logic
• Improve consistency and reliability across CMS eCQMs

Rather than defining commonly used logic within every individual measure, eCQMs reference the CQMCommonQDM library to leverage centrally maintained functions and expressions. This approach improves maintainability by allowing common logic enhancements or corrections to be made in a single shared library rather than across numerous individual measure libraries.

The CQMCommonQDM library, along with its CQL source and generated Expression Logic Model (ELM) files, is published with the annual eCQM release and is available from the eCQI Resource Center under the eCQMs section for each CMS reporting program (for example, Eligible Clinician eCQMs). It is also included as part of the published measure packages for measures that reference the library.