QI-Core – Quality Improvement Core

Clinical Decision Support (CDS) Connect is a freely available web-based platform, including an authoring tool and a repository, enabling the CDS community to identify evidence-based care, translate and codify information into an interoperable health information technology standard, and leverage tooling to promote a collaborative model of CDS development.

*Note: On April 28th, 2025, AHRQ’s CDS Connect went offline. An updated, likely final version of its authoring tool has been developed by the HL7® community as CDS Connect Community Edition. A newer set of tools, the open source CQL Studio, is an integrated web application suite for developing, testing, and publication of CQL- and FHIR-based artifacts that can be developed into computable guidelines, CDS, or dQMs, providing a functional superset of capabilities.

The Clinical Quality Language (CQL) Evaluation Engine is an open source Java-based evaluation engine capable of evaluating the result of any CQL expression. Note: this is a component in the CQL translator repository.

Clinical Quality Language (CQL) Execution Framework is the engine that runs the rules and expressions defined in CQL to evaluate electronic clinical quality measures (eCQMs), decision support logic, or other healthcare-related computations.

The Clinical Quality Language (CQL) Formatting and Usage Wiki is a collaborative, community-driven workspace dedicated to the development and sharing of CQL formatting conventions, coding patterns, and best practices. It serves as a central resource for measure developers, health information technology (IT) implementers, and clinical informaticists to standardize how CQL logic is represented within electronic clinical quality measures (eCQMs) and other clinical decision support artifacts. The Wiki provides practical guidance on writing clear, consistent, and maintainable CQL, including examples, templates, and usage recommendations, helping ensure that quality measure logic is accurately interpreted, interoperable, and easier to implement across different health IT systems.

Clinical Quality Language (CQL) Runner is an online platform for ad hoc testing of CQL.

The CQL-to-ELM Translator is an open-source reference implementation that translates the high-level Clinical Quality Language (CQL) source into the Expression Logical Model (ELM), a machine-readable representation of CQL logic. The translator supports syntactic and semantic validation of CQL and can generate ELM in XML or JavaScript Object Notation (JSON) format. Developed as part of the Clinical Quality Framework (CQF) effort, it supports consistent implementation of CQL-based artifacts by providing a standardized intermediate representation that can be used by authoring tools, validation tools, and CQL execution engines.

For more information or to get involved, visit the Clinical Quality Framework initiative page.

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.

This Health Level Seven International® (HL7®) Clinical Quality Language (CQL)-Health Quality Measure Format (HQMF) Implementation Guide (IG) defines an approach to using CQL with the Quality Data Model (QDM) and HQMF to define electronic clinical quality measures (eCQMs). The IG describes the use of CQL to express the logic and the US Domain conceptual data model, QDM, to express the individual data types and their attributes for an eCQM detailed using the HQMF standard.

The Office of the National Coordinator for Health Information Technology (ONC) Project Tracking System uses Jira, a project management and issue-tracking platform developed by Atlassian.

This system provides a centralized and transparent platform for users to log, track, and discuss issues with subject matter experts across a broad range of topics including: Hybrid Measures, CQL, Cypress, eCQMs, MADiE, QDM, QRDA, and USCDI+ Quality (FHIR/dQM projects coming soon). CMS uses the system throughout the development, implementation, and maintenance stages of the measure lifecycle.

A 90-day account deactivation policy is enforced for users who have not logged into the system for 90 consecutive days or longer.

The Quality Data Model (QDM)-based Clinical Quality Language (CQL) Style Guide provides standardized expressions of electronic clinical quality measure (eCQM) concepts across eCQMs and defines a uniform “look and feel” to eCQM logic. The QDM-based CQL Style Guide focuses on a set of common best practices that have been implemented across QDM-based eCQMs in CMS quality reporting programs. The QDM-based CQL Style Guide also promotes the use of consistent language within the framework of CQL, including libraries, aliases, definitions, and functions, and provides guidance on other conventions, such as operator precedence. eCQM stewards or developers who are developing or specifying eCQMs for potential inclusion in CMS reporting programs should follow these best practices.

Visual Studio Code is an open-source text editor that can expand its utility by installing appropriate extensions. The ‘cqframework.cql’ extension supports highlighting, syntax checking, ad hoc evaluation, test cases, terminology for Clinical Quality Language (CQL), and Fast Healthcare Interoperability Resources® model validation. This free text editor can be used to facilitate electronic clinical quality measure evaluation and testing using the open source CQL Evaluation Engine.