CIMI Architecture: Informatics View

The Clinical Logical Information Model (CLIM) consists of the three Basic Meta Model (BMM) reference model layers and two archetype layers shown here.

The CIMI Reference Model is expressed using the OpenEHR Basic Metamodel (BMM) Language. The archetype layers are expressed using the OpenEHR Archetype Definition Language (ADL). While reference model modules define classes, attributes, and class hierarchies, the archetype layers only specify progressive constraints on the reference model but do not introduce new classes, attributes, and class-class relationships.

1. The CIMI Core Reference Model provides the core granularity of the CIMI model and introduces its top-level classes such as the DATA_VALUE class and the LOCATABLE class. This reference layer module defines the CIMI primitive types and core data types.
2. The CIMI Foundational Reference Model is closely aligned to ISO13606 and the OpenEHR Core Reference Model. It defines foundational CIMI clinical documents and clinical record patterns. It also introduces the PARTY, ROLE, and PARTY_RELATIONSHIP patterns and defines the top-level CLUSTER class for complex CIMI type hierarchies. CQI Knowledge Artifacts may also leverage this layer.
3. The CIMI Clinical Reference Model consists of the classes derived from existing CIMI archetypes, the FHIM, QUICK, vMR, and QDM. This layer defines the set of 'schematic anchors' (to borrow Richard Esmond's term) or core reference model patterns from which all CIMI archetype hierarchies and ultimately Detailed Clinical Models (DCMs) derive. Requirements for this layer come from FHIM, vMR, QDM, QUICK, FHIR US Core, SDC, etc...
   1. The 'goal' is to define the reference models with low FHIR transformation costs where feasible noting that we will inherently have some divergence due to the different requirements underlying both models.
   2. Galen points out that, FHIM’s expressivity will not carry over to CIMI DCMs given the models' different requirements (e.g., FHIM includes finance and accounting).
4. The CIMI Foundational Archetypes define the top-level constraints on the CIMI Reference Model. These typically consist of attribute formal documentation and high level attribute semantic and value set bindings. Archetypes at this layer will provide the foundational requirements for future US Core and QI Core profiles. Future pilots will explore the generation of US Core and QI Core archetypes from these CIMI archetypes.
5. The CIMI Detailed Clinical Model Layer represents the set of leaf-level constraining profiles on the foundational archetypes to create families of archetypes that only vary in their finest terminology bindings and cardinality constraints. This layer is intended to support clinical interoperability through an unambiguous specification of model constraints for information exchange, information retrieval, and data processing.

From layers 1-5, we define the set of transformations (e.g., SIGG (MDHT, MDMI)) to generate the corresponding FHIR profiles including the US Core and QI Core profile sets. Note that FHIR profiles can be generated from the various levels of the archetype hierarchy depending on requirements. The lower down in the hierarchy, the more prescriptive the profile is in terms of constraints. Much like ADL Archetypes, FHIR profiles can be layered.

It is important to note that some FHIR profiles may be derived from the Foundational Archetype Layer (e.g., US Core, some QI Core profiles, some CQIF profiles on PlanDefinition, Questionnaire and ActivityDefinition, etc...) and others from the DCM Layer (e.g., bilirubin, HgA1c, etc...). In other words, the arrow for FHIR Profiles stems out of the outer box rather than the last of the inner boxes (the DCM box).