Getting Started with eCQMs

Many different organizations may participate in the development and maintenance of electronic clinical quality 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 lifecycle 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 stages eCQMs progress through development (conceptualization, specification, and testing), implementation, and maintenance. CMS and measure developers provide 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 eCQMs users 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. Use the Change Review Process (CRP) Guide to participate in the eCQM updates.

Structure of eCQMs

To facilitate reporting from an electronic health record (EHR) and/or other health information technology, eCQMs are made of electronic specifications. Health Quality Measure Format (HQMF), CQL, Expression Logical Model (ELM), and other Health Level Seven International® (HL7) standards, are used for electronically documenting eCQM content. 

Coding of information for eCQMs consists of

• Computable representations of the eCQM, which contain important details about the measure, the definition of the data elements, 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 MAT User Guide, Chapter 6: Measure Details discusses the metadata, which populates the header. The HQMF body contains eCQM sections (e.g., definitions, population criteria, supplemental data elements).
  • 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 referenced from HQMF.
    • CQL file (.cql). The CQL file 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 organized into libraries for reusing or sharing between measures and other artifacts.
    • Expression Logical Model (ELM) XML document (.xml). ELM provides a machine-readable representation of the measure’s logic in XML. The intent of the ELM file is for machine processing and provides the information needed to retrieve data from an EHR automatically.
    • ELM JavaScript Object Notation (JSON) file (.json). The JSON file is the ELM file in JavaScript Notation, as opposed to XML.
• Human-readable representation of the eCQM displays the eCQM content in a human-readable format directly in a web browser, Hypertext 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 an extraction from the HQMF header.
• Value sets and direct reference codes (DRCs) convey specific coded value(s) allowed for the data elements within the eCQM. Identification of value sets is via an object identifier (OID) and each value set includes several metadata elements that describe the inclusion and exclusion criteria for the codes in the set. 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 referenced directly in the eCQM logic to describe a data element or one of its attributes. Find value sets and DRCs in the 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 in front of the number. The eCQM Version Number indicates 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. Use the eCQM Naming and Terminology Guide for guidance regarding common words, phrases, and technical terms used in conjunction with eCQMs.