Understanding OpenEHR Clinical Knowledge Manager

Health data interoperability is the ability to share and interpret data between different health systems being comprised of predominantly two levels namely syntactic interoperability-the ability to share information between two systems and semantic interoperability- the ability to preserve the meaning of data while being exchanged.

OpenEHR is an open standard specification in the field of health informatics that ensures universal interoperability among all forms of electronic data. It describes the management, storage, retrieval, and exchange of health data amongst various EHRs.

OpenEHR architecture is based on a well-known two-level design paradigm that fit well with the basic principles of syntactic and semantic interoperability namely the Reference Model that ensures syntactic interoperability and the Clinical Information Models (CIMs) that ensures semantic interoperability. A key feature of openEHR is the development of computable, human-readable, discrete clinical models with associated terminologies to represent health data known as Archetypes. Archetypes have been created based on the principles of Reference Model and since it represents a discrete clinical concept which will always have the same meaning regardless of context, what system or what language is being used, it can be said that “archetypes are building blocks created to execute the principles of both syntactic as well as semantic interoperability”. Examples of such clinical concepts include heart rate, blood pressure.

Combination of two or more such archetypes lead to the creation of what is referred to as “Templates”. Therefore Templates, composed of one or more archetypes, with further added constraints as per a particular setting, are a further means of building clinical models.

These clinical concepts (Archetype and Templates) are publicly available to be used and implemented within health information systems, in an online repository known as the openEHR Clinical Knowledge Manager (CKM).

The openEHR CKM is a health data management application and repository of clinical concepts developed with the goal to create a coherent health data ecosystem that promotes sharing/re-using of such clinical concepts across multiple clinical scenarios. Such an approach can potentially establish a universal health language that can link disparate health systems a crucial step in realizing the most coveted semantic interoperability.

The figure below is a pictorial representation of the role that CKM plays in the overall bigger picture of health data interoperability:

OpenEHR CKM in simpler terms can be understood as an online repository of openEHR archetypes. When the end user enters a term, the CKM will return the archetype that contains the word in metadata, definition, or ontology section. The identified archetypes within the CKM are can be eventually constrained to create larger building blocks of clinical content called Templates.

Over the years, the CKM (also known as International openEHR CKM) keeps updating versions for the different archetypes, having a very well-structured management of the archetype’s lifecycles, with new versions being approved after a community consensus.

The first introduction of CKM had as main objective the creation of an archetype library, development of a review process with achieved content consensus, publication and governance of the artifacts. Since then, templates and terminologies including terminology specific subsets (SNOMED-CT, LOINC, ICD) have been included.

The CKM now has a model governance system that supports all the life cycle of archetypes, templates and terminology.

Functions of OpenEHR CKM can be summarized as below:

The CKM is a critical enabler: an online hub providing a shared library of archetypes and templates; a collaboration portal receiving contributions of models and expertise from the international member community; and a governance tool to manage clinical content publication, language translation, and artifact versioning.

Prior to the onset of the Covid 19 pandemic, OpenEHR’s CKM focused on creating a library of shared archetypes. Templates had been uploaded to CKM, most commonly to demonstrate modeling patterns or to provide exemplars for common types of data sets. The onset of the COVID-19 pandemic triggered a collaborative openEHR community effort to fast track both archetype and template development, with CKM used as a coordinating hub.

Over a period of time the archetypes within the CKM library are expected to grow with enhanced quality, greater details, refined with iterated peer reviews, underpinned by a robust governance. Today the CKM houses 500+ archetypes and 8000+ data elements. With this in place it is plausible to imagine the potential that this exhaustive library of standardized, coordinated, and coherent information models holds to be able to represent a broader and more diverse range of data sets.

This blog attempted to discuss the role that openEHR CKM plays in the overall bigger picture of enabling health data interoperability. The next blog post will include in detail the different classes of Archetypes being hosted by the CKM as well as the life cycle that a typical Archetype undergoes within the CKM.