HL7 FHIR In OpenIZ

In the previous post, we discussed the rationale of using the HL7 Reference Information Model (RIM) for our primary information model in OpenIZ, in this post we'll explore how OpenIZ exposes core data via HL7 FHIR.

While the RIM is used as an information model in the solution, the RIM is (unfortunately) quite verbose for expression over the wire. Anyone who has implemented HL7 CDA or HL7v3 will tell you this. That is why we only expose the RIM over REST whenever another system requires 1:1 representation (like the disconnected client).

For most other interactions with the IMS, HL7 FHIR is quite capable. It allows third party developers to access the clinical information in the IMS without having to worry about the complexities of the RIM (what is a mood code anyways?).

The OpenIZ implementation of HL7 FHIR has focused primarily on read-only transactions. The rationale for read-first focus is that quite a bit of work has to be done to ensure that data written using FHIR will comply with the RIM.

Currently OpenIZ supports the following resources on our /fhir interface (all are STU3):

• Immunization - Which provides query access to vaccination events in the IMS
• ImmunizationRecommendation - Which allows FHIR clients to execute the care planning service
• MedicationAdministration - Which provides query access to non-immunization medication events such as supplements.
• Observation - Providing queries to observation events (both coded and quantitative)
• Patient - Allowing for the querying of patients in the OpenIZ system
• AdverseEvent - Which provides facilities for querying Adverse Events Following Immunization (AEFI) events
• AllergyIntolerance - Providing access to problem concern or allergy information in the IMS
• Condition - Which allows fetching of clinical conditions, reactions, symptoms, etc.
• Location - Providing complete access to places stored in the OpenIZ IMS
• Medication - Which allows querying for individual medication lots in the system
• Substance - We've mapped substances to the type of substances which can be encountered in the IMS.
• Provider - Which maps to the physicians or clinicians which provide care in the IMS

We hope to provide additional resources (especially infrastructure like conformance and value set) in the coming months. Look for OpenIZ at a FHIR connect-a-thon soon!