Archetyping CDISC ODM

Every standard or specification with the notion of clinical document (or even the more visual metaphor of "form") is a potential candidate to be used in a dual model way (reference model + archetypes). CDISC ODM is not an exception. In fact, CDISC kind of mimics this by including both the study information (the "archetype") and the collected data in the instance sent to the server. This is something we will explore a little further later on.

First, to create CDISC ODM archetypes, CDISC ODM reference model must be included in LinkEHR. The reference model can be imported from CDISC ODM XML Schemas, in a similar way we imported HL7 FHIR XML Schemas. As we have already imported the schemas into LinkEHR you can also import directly the RM file in LinkEHR Reference Model Manager. For convenience, the RM file is available in LinkEHR downloads page. By creating CDISC archetypes we can take advantage of all the capabilities and tooling available for working with archetypes.

Archetypes are constraints over data, in reality CDISC ODM archetypes should replicate what is already going in the <Study> part of the ODM and store them as constraints over clinicalData. Good think is that this process can be completely automated. We created a method that traverses the XML study info and generates the corresponding constraints.

Original XML study

Transformed ADL

Same methodology could be used to generate the inverse process (going from clinicalData in ADL to XML study definition). The use of archetypes in this context has several advantages, such as multilinguality (study could be exported to any given language), terminology binding, more powerful constraint and rule definition (for data validation and generation), and of course, the automatic generation of transformation programs from mappings to other standards or models. Probably I will need to create in the future a blog post or video tutorial about this last point, as it seems to be quite an unknown part of LinkEHR :)

Another interesting use case could be the automatic transformation of openEHR or ISO13606 archetypes into CDISC ODM archetypes (or XML studies), which seem to be feasible as long as the user can define which parts of the archetype wants to include in the study, probably selecting Sections as different FormDef/ItemGroupDef. In the same way, CDISC data could be transformed into ISO13606 or openEHR Integration Information Model to allow archetype-based queries and import it into an organization workflow.

By the way, the use of archetypes with CDISC ODM is something we have been exploring since before 2014. I really recommend you to take a look at that presentation if you are interested. Everything told there still holds today. Maybe you have to change mentally the mentions to HL7 v2 and CDA to FHIR to update it to currently used standards :)  

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