eCQMs

Many different organizations may participate in the development and maintenance of electronic clinical measures (eCQMs). The CMS Measures Management System is a standardized system and provides details on the process for developing and maintaining the quality measures used in CMS's various quality reporting and incentive programs. Information on the clinical quality measure and eCQM is available in the Blueprint for the CMS Measures Management System (Blueprint) and on the eCQM Lifecycle webpage. The Clinical Quality Language (CQL) Style Guide is for use by measure developers. It provides examples to standardize expression of measure concepts across eCQMs and define a uniform look and feel to eCQM logic using CQL. The Guide provides a set of common best practices for implementation across CQL-based eCQMs used in CMS quality reporting and incentive programs. 

eCQM Lifecycle:

The eCQM Lifecycle is a series of phases eCQMs progress through when being developed, tested, implemented, and updated. CMS provides several opportunities for stakeholders to engage throughout the measure lifecycle. 

Updates to eCQMs:  

CMS requires eCQMs approved for CMS programs to be updated annually to reflect changes in evidence-based medicine, code sets, and measure logic. CMS works with measure stewards, measure developers, and users of the eCQMs to ensure necessary changes are reflected in the Annual Update. Additionally, CMS may provide addenda to the eCQM Annual Update periodically within the year to ensure updated code systems are reflected in the eCQM specifications and supporting materials.

Structure of eCQMs:

To be reported from an electronic health record (EHR), eCQMs are made of electronic specifications. Health Quality Measure Format (HQMF), CQL, and Expression Logical Model (ELM), Health Level Seven International® (HL7) standards, are used for electronically documenting eCQM content. These electronic specifications include

• Computable representations of the eCQM, which contain important details about the measure, how the data elements are defined, and the underlying logic of the measure calculation. The files include:

  • HQMF XML syntax (.xml). The HQMF includes a header and a body. The header identifies and classifies the document and provides important metadata about the measure. The HQMF body contains eCQM sections (e.g., definitions, population criteria, supplemental data elements).

  • CQL file (.cql). Provides the expression logic for data criteria, population criteria, and supplemental data elements. It provides a formal description of the computable content in the measure and is organized into libraries that can be reused or shared between measures and other artifacts.

  • Shared CQL libraries (.cql, .xml, and .json). The shared libraries are the basic units of sharing CQL. They consist of a foundation of CQL statements used within a measure. Every measure has at least one main CQL library and is referenced from HQMF.

  • ELM XML document (.xml). Provides a machine-readable representation of the measure’s logic in XML. The ELM file is intended for machine processing and provides the information needed to automatically retrieve data from an EHR.

  • ELM JavaScript Object Notation (JSON) file (.json). The JSON file is the ELM file in JavaScript Notation, as opposed to XML.

• The Human-readable representation of the eCQM displays the eCQM content in a human-readable format directly in a web browser, Hyper Text Markup Language (HTML) file (.html). This file does not include the underlying HQMF syntax, but the narrative content at the top of the HTML is extracted from the HQMF header.

• A value set and a direct reference code (DRC) convey specific coded values that are allowed for the data elements within the eCQM. Value sets are identified by an object identifier (OID) and include several metadata elements. The value set includes a list of codes (i.e., the value set “expansion code set”) acceptable or valid for a specific data element in the measure, descriptors of those codes, the code system from which the codes are derived, and the version of that code system. DRCs are specific codes that are referenced directly in the eCQM logic to describe a data element or one of its attributes. Value sets and DRCs are found in the Value Set Authority Center (VSAC).   

Naming eCQMs:

CMS created a unique “CMS eCQM Identifier” to name eCQM files. The naming convention adds the eCQM identifier assigned to the eCQM in the Measure Authoring Tool (MAT) with the “eCQM Version Number”. “CMS” is placed in front of the number. The eCQM Version Number is used to indicate the published version of the eCQM. For example, based on this naming convention, eligible professional measure (NQF0056-Diabetes: Foot Exam) would be CMS123v1 for the first version of the measure.