Clinical Quality Language Release 1
This page is part of the Clinical Quality Language Specification (v1.5.2: Normative - Normative) based on FHIR R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions 
| Clinical Decision Support Work Group | Maturity Level: N/A | Standards Status: Informative |
As part of the Clinical Quality Framework effort, reference implementations of a CQL-to-ELM translator, a native ELM execution engine, and other CQL-related tools are maintained. This appendix provides a brief overview of where to find more information on these reference implementations.
The CQL-to-ELM Translator is a reference implementation for the translation of text-based CQL library documents into an XML or JSON representation using the ELM. In addition to being developed and used as part of CQF pilots, the translator has been integrated into production authoring environments for both Clinical Decision Support and Clinical Quality Measurement. The implementation can also be used as the first step in a process to enable distribution, translation, execution, and integration of CQL-based quality artifacts.
The CQL-to-ELM Translator is licensed under the open source Apache Version 2.0 license, and available as part of the clinical_quality_language project on GitHub: https://github.com/cqframework/clinical_quality_language, as well as a Maven Package (Snapshots).
For an overview of the project, along with current status, refer to the following document:
A reference implementation for executing CQL is currently under development. This reference implementation was used in CQF pilots and has been integrated into production eCQM testing tools.
The CQL execution framework is licensed under the open source Apache Version 2.0 license, and available as part of the clinical_quality_language project on GitHub: https://github.com/cqframework/cql-execution.
For an overview of the project along with current status, refer to the following document:
Other CQL-related tools such as a graphical CQL grammar parsetree viewer, a ModelInfo generator, and a CQL syntax highlighting plugin for Atom are also available. The Clinical Quality Framework Initiative maintains a list of known Community Projects on the CQL Github Wiki:
https://github.com/cqframework/clinical_quality_language: CQL-to-ELM Translator
https://github.com/cqframework/cql-execution: Java-Script Execution Engine
https://github.com/cqframework/cql-exec-fhir: A FHIR data source provider for the CQL Execution framework
https://github.com/cqframework/cql-exec-vsac: A VSAC-enabled value set provider for the CQL Execution framework
https://github.com/cqframework/cql-exec-examples: Simple examples demonstrating how to use cql-execution, cql-exec-fhir, and cql-exec-vsac
https://github.com/cqframework/cql-translation-service: RESTful service for translating CQL to ELM
https://github.com/AHRQ-CDS/AHRQ-CDS-Connect-CQL-SERVICES: Expose CQL via Custom-API or CDS Hooks interface (built on JavaScript CQL Execution Engine)
https://cds.ahrq.gov/: Repository of CDS including CQL-based artifacts
https://cds.ahrq.gov/authoring/: CDS Authoring Tool capable of exporting FHIR-based CQL logic
https://github.com/AHRQ-CDS/AHRQ-CDS-Connect-Authoring-Tool: CDS Authoring Tool Source Code
https://github.com/samply/blaze: A FHIR® server with internal, fast CQL Evaluation Engine
https://github.com/dbcg/cqf-ruler: HAPI FHIR server plugin to enable CQL evaluation and Clinical Reasoning functionality
https://github.com/PheMA/cql-on-omop: Translates CQL (ELM) to OMOP for evaluation against an OHDSI repository
https://github.com/cqframework/cqf-tooling: Tooling to support CQL library tooling and other handy utilities related to CQL-based FHIR content