Both openEHR and ISO 13606 share a common foundation: the Archetype Object Model (AOM). The AOM is a two-level modelling approach that separates technical structures (the reference model) from clinical knowledge (archetypes). Archetypes define domain-specific content like clinical observations, diagnoses, or medication lists, while the reference model provides the generic framework for handling health information. This two-level modelling allows healthcare organisations to build flexible, adaptable systems that can evolve without needing to modify underlying software code. Originally developed by the openEHR community, the AOM became part of the ISO 13606 specification, which is one reason why these two standards are often associated with each other.
One of the core differences between openEHR and ISO 13606 is in their scope and purpose. openEHR is primarily a standard for the persistence and querying of electronic health records (EHRs). It is designed to enable long-term storage of clinical data, supporting complex data retrieval, clinical decision-making, and the management of longitudinal health records. In contrast, ISO 13606 focuses on data communication and exchange, aiming to standardise the structure of health data when it is transferred between different systems, such as hospitals, clinics, or national healthcare networks. In this way, it serves a similar purpose to other communication-focused standards like HL7 CDA or FHIR. The difference in purpose—openEHR for data persistence and ISO 13606 for data communication—shapes the design of both standards and is one of the primary reasons they have distinct technical models.
Although both standards share a high-level conceptual framework, their reference models differ significantly in detail. At first glance, the reference models of openEHR and ISO 13606 appear similar; both use concepts such as Compositions, Sections, Entries, and Elements to structure clinical data. However, these similar terms mask the underlying differences in how each standard organises and handles information. openEHR’s reference model is designed to handle the complexities of long-term data persistence, supporting a wide range of clinical scenarios. It offers a detailed structure with rich data types, complex relationships between elements, and mechanisms for version control and querying. On the other hand, ISO 13606’s reference model is optimised for data transmission and is therefore more streamlined. While it shares the same basic framework, the actual implementation—such as the data types and relationships used—is designed for communication rather than storage.
Both openEHR and ISO 13606 rely on archetypes to define clinical content, but their archetypes are not interchangeable. While both use the Archetype Object Model (AOM) as their foundational method, the archetypes developed for openEHR and ISO 13606 are specific to their respective reference models. openEHR archetypes are tailored to its more detailed, complex structure, designed for persistent data storage and retrieval. In contrast, ISO 13606 archetypes are designed for interoperability and communication between systems. The different purposes of each standard result in archetypes that are not directly compatible, requiring transformations or mappings if data needs to move between systems based on these two models.
Despite these differences, some tooling is shared between the two standards. Both openEHR and ISO 13606 rely on a common model described in Part 2 of the ISO 13606 standard, which defines the structure of archetypes. This shared model allows for the use of similar tools, such as archetype editors, across both standards. However, because the underlying reference models differ, specific configurations or transformations are often required when adapting archetypes to either openEHR or ISO 13606. This means that while tooling can help bridge some of the gaps, it does not resolve all the differences between the two systems.
In terms of use cases, openEHR and ISO 13606 are applied in different contexts based on their respective strengths. openEHR is ideal for healthcare organisations that require long-term data management, complex data querying, and clinical decision support. It is commonly used in national health record systems and large hospital networks, where persistent, comprehensive health data is crucial. In contrast, ISO 13606 is more suited for environments where the exchange of health data is a priority. Its focus on communication makes it useful in health information exchanges (HIEs) or cross-border healthcare systems, where data must move efficiently between different organisations or jurisdictions.
In conclusion, while openEHR and ISO 13606 share a common heritage and are both based on the Archetype Object Model, they serve distinct purposes. openEHR is primarily a standard for the persistence and querying of health records, while ISO 13606 is focused on the communication and exchange of clinical data. Their reference models and archetypes, though conceptually similar, differ significantly in the details, reflecting these distinct goals. Understanding these differences is crucial for healthcare organisations and software developers working in health informatics and striving to achieve system interoperability.
