Combining Archetypes with FHIR in Future-proof Health Information Systems

Diego Boscá, David Moner, Jose Alberto Maldonado, Montserrat Robles

Biomedical Informatics Group (IBIME)Institute for the Application of Advanced Information and Communication Technologies (ITACA)

Universitat Politècnica de Valencia, Spain

diebosto@upv.es

Objective

• Can archetype methodology be used seamless in FHIR workflow and FHIR used in archetype systems?1. Create archetypes based on FHIR model2. Use the archetypes for the generation of data transformation

programs between archetype-based standards and FHIR (and vice versa)

3. Use archetypes and their transformations alongside FHIR Resources in a FHIR server.

Achieve semantic interoperability between the most future-proof clinical information exchange standards.

What are archetypes?

• A reference model provides the pieces and basic structure to represent any clinical data and its context information (dates, authorship, etc.).

3

Reminder

aboutarchetypes

• A dual model architecture separates the representation of data structures from their formal definitions.

ISO EN 13606

HL7 CDA FHIR

• An archetype represents the instructions about how to combine those pieces into a data structure schema that also has a clinical defined meaning (e.g. a discharge report or a medication instruction).

openEHR

What is FHIR?

• FHIR is a brand new HL7 DSTU for the electronic exchange of healthcare information.– FHIR is based on a set of basic modular components called Resources,

which are reusable patterns defined and represented in a common way, based on a set of data types.

– Resources can be used by themselves, extended, or combined to satisfy the majority of common user cases.

• FHIR approach is similar to the dual model approach used in ISO13606 and openEHR.– Both define reusable clinical models to describe clinical information.– Main difference: Archetypes describe maximal datasets, as they aim to

document all the information about a given clinical domain. FHIR is based on the 80-20 principle where an element will be included only if 80% of the systems implement it.

1. FHIR Resources as Archetypes

• For the generation of FHIR archetypes we must define a Reference Model (RM) first.

• We derive FHIR RM automatically from the FHIR definition (Ecore/XML Schemas)

Base of

FHIR Ecore/XML Schema

Transformed into

FHIR archetypes / extended resources

FHIR Reference Model Archetype

Defined in

FHIR Resource

1. FHIR Resources as Archetypes

• The creation of the RM allows us to define FHIR archetypes

• These archetypes can be seen as FHIR Profiles or extended Resources.

1. FHIR Resources as Archetypes

2. Mapping to FHIR archetype

• Having available the FHIR RM allows us to generate data transformation programs from the archetypes.

• Our data transformation programs assure the data follows both the archetype constraints and the RM constraints.– The mapping is made over an automatically created merged archetype

(archetype + RM). This merged archetype can be mapped to a data source or another archetype.

2. Mapping to FHIR archetype

XQuery program

Archetype-based data

FHIR data

2. Mapping from FHIR archetype

• We can apply exactly the same methodology for the transformation of FHIR resources and profiles to other standards.– FHIR archetypes can be used as a source of the mapping process.

• Seamless integration of FHIR data into current archetype-based systems

3. FHIR + Archetypes data server

• We reuse FHIR REST API for interacting with an archetype-based server.– In the parts of the API where the Resource name is used, the identifier

could be used in their place.– Resources can define additional query parameters in the profiles. We

take advantage of this to support the definition of query parameters for archetypes.

FHIRServer

HL7 CDAServer ISO13606

Server

FHIR

Wrapper

FHIR

REST Q

uery

FHIR REST Query

FHIR REST Query

openEHRServer

FHIR REST Query

3. FHIR + Archetypes data server

• Proof of concept FHIR server– Query using FHIR Resources or archetype identifiers– Profiles can be generated from the archetypes in order to tell the

server the available query parameters.

• Test queries:http://diebosto2.pc.upv.es:8080/FHIRServer/rest/test/openEHR-EHR-

OBSERVATION.blood_pressure.v1?systolic=>80&diastolic=<100

http://diebosto2.pc.upv.es:8080/FHIRServer/rest/test/openEHR-EHR-EVALUATION.problem-diagnosis.v1?diagnosis=195967001

http://diebosto2.pc.upv.es:8080/FHIRServer/rest/test/Patient?gender=M

Advantages

• Being able to check if a resource is valid against the reference model (useful for evolving specifications as FHIR DSTU).

• Profile consistency is already solved.• Lock down modeling optionality and vocabularies.• Knowledge reuse.• Multilinguality.• Generation of derived reference materials (such as schematron,

JSON-Schema, mindmaps, sample formularies or implementation guides).

• Use of AQL to query FHIR archetype based data.• Reuse of current tooling for:

– Resource creation.– Data transformation (legacy & non-legacy).– Profile sharing and evolution.

Disadvantages

• In addition to XML, FHIR makes heavy use of JSON which is not yet supported natively in our XML oriented implementation.

• The narrative parts of FHIR (constraints over pseudo-HTML code) are difficult to handle in archetypes

• Further upgrades and testing are needed to be compliant with FHIR DSTU2.

Archetypes are in FHIR

• FHIR can be used in archetype based systems, using already available methodologies and tools

• Archetype based systems can easily provide FHIR APIs to create, retrieve, update, delete, and query an archetype based system.

• This can be beneficial for both FHIR and archetype based systems as allows FHIR enabled applications to use already defined clinical models but also helps archetype based systems to get more visibility in the HL7 world.

Diego Boscá Tomás

Grupo de Informática Biomédica (IBIME)Instituto ITACA, Universitat Politècnica de Valencia, Spain

diebosto@ibime.upv.eshttp://www.ibime.upv.es/