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CDS/eCQM Harmonization

How are CDS & eCQM different?

Clinical Decision Support (CDS) and electronic Clinical Quality Measures (eCQMs) are closely related, share many common requirements, and support health care quality improvement. It’s important to also understand the differences between them and the efforts to help them work together (harmonization). The standards used for the electronic representation of CDS and eCQM were initially developed separately and used different data models and computable expression languages. The use of different standards

  • Makes re-using or sharing machine readable logic between eCQMs and CDS rules very difficult
  • Creates a burden for health information technology (IT) developers and those who provide technical support for implementation

Beginning with the eCQMs intended for implementation in calendar year 2019, Health Level Seven International® (HL7) Clinical Quality Language (CQL) replaced the Quality Data Model (QDM) as the preferred eCQM expression language.  CQL is an authoring language standard that provides the ability to express clinical logic that is both human-readable and machine-readable via a structured representation. Since CDS also uses CQL, this closes the gap on the differences between CDS and eCQMs.

Why harmonize CDS & eCQM?

Harmonization of CDS and eCQM standards will improve the ease of implementation. Harmonization will also make it easier to integrate and facilitate health IT-enabled clinical quality improvement since the functions of CDS and eCQMs are complementary. FHIR and CQL provide a common foundation for representing CDS and eCQMs to

  • Suggest care to clinicians and care teams when there are opportunities to improve care quality
  • Measure if appropriate care was given

Who is harmonizing CDS & eCQM?

To learn more about this effort, please visit the HL7 Clinical Quality Framework (CQF) Wiki. CQF is an HL7 project led by the CDS and Clinical Quality Information Work Groups to identify, develop, and harmonize standards that promote integration and reuse between CDS and eCQM. Read the HL7 FHIR Informative Whitepaper. Note that this document requires a HL7 account, but not HL7 membership.


The HL7 FHIR Specification is a standard for exchanging healthcare information electronically. The CQF Initiative has developed various FHIR resources, profiles, and implementation guidance to represent quality measures and decision support artifacts. These resources are

  • Consistent with the Common Metadata Standard, and can use CQL to represent expression logic, and the QI-Core Framework profiles to represent clinical information.
  • Defined and introduced as part of the Clinical Reasoning Module of the Standard for Trial Use (STU) 3 version, currently R4 (Mixed Normative and Trial Use), of the FHIR standard. 
  • Being used and tested in a variety of settings, including FHIR Connectathons and ongoing pilots, to validate that they can effectively fulfill the need for a single set of standards to support delivery of both decision support and quality measurement artifacts.

To learn more about this effort, please visit FHIR section of this website.

The table outlines the common areas and differing standards currently used in CDS and eCQMs.

  Patient and Clinical Data Computable Expression Logic Metadata and Structure Evaluation Model

Quality Improvement (QI)-Core (for Fast Healthcare Interoperability Resources® [FHIR]-based CDS)


FHIR Clinical Reasoning

FHIR Clinical Guidelines

CDS Hooks (for FHIR-based CDS)


Quality Data Model (QDM)


Health Quality Measure Format

Quality Reporting Document Architecture

Common Shared Standards

Common Shared Standards

The strategy employed by the CQF Initiative is to identify the common components used by each domain and define common standards for each of the core components.  

To date, these efforts have produced specifications for these common elements:

QI-Core (Quality Improvement-Core Framework) is a US Realm Implementation Guide (IG) of the FHIR Specification that defines a uniform way for quality measurement and decision support knowledge to refer to clinical data. The profiles align as much as possible with the Data Access Framework and incorporate content from the QDM and the vMR specifications.

The QI-Core IG defines a set of FHIR profiles with extensions and bindings needed to create interoperable, quality-focused applications. The profiles in this IG derive from and extend the US Core profiles to provide a common foundation for building, sharing, and evaluating knowledge artifacts across quality improvement efforts in the US Realm.

As an HL7 FHIR IG, changes to this specification are managed by the sponsoring workgroup, Clinical Quality Information, and incorporated as part of the standard balloting process. The current roadmap follows closely behind the base FHIR roadmap and the US Core IG.

Last Updated: Feb 23, 2021