Guideline Definition Language (GDL)

The Guideline Definition Language (GDL) is a formal language used to express clinical rules and guidelines in a machine-readable format.

The language was created to enable development of highly portable computerized Clinical Decision Support (CDS) logic and modules by leveraging semantically interoperable Electronic Health Record (EHR) standards. It is the language of choice for the GDL Editor software, developed by Cambio Healthcare Systems, that utilizes openEHR archetypes to model clinical practice guidelines for computerized CDS. Due to the interoperable nature of openEHR archetypes, the resulting GDL files – referred to as guides or guidelines – are platform independent and agnostic to both natural languages and reference terminologies.

For more detailed information regarding the GDL, please proceed to the specification page.


The Medical Informatics Group (MIG) at Cambio Healthcare Systems was founded in 2013 and partnered with the openEHR Foundation to release the first specification of the Guideline Definition Language (GDL) during the same year. Since then, the language has been used to model over 400 clinical decision support (CDS) applications that are available in our GitHub repository for anyone to use.


The Guideline Definition Language (GDL) is a formal language for expressing clinical decision support logic. It is designed to be agnostic to natural languages and reference terminologies by leveraging the designs of the openEHR Reference Model and Archetype Model.


The Guideline Definition Language (GDL) has been studied, compared and evaluated in several independent academic publications in recent years. A list of publications is available and ranges from PhD and Master theses to scientific articles published in academic journals.