Overview

If you've never worked with FHIR before, converting HL7 v2.x messages to FHIR resources may seem a daunting task. However the FHIR documentation actually provides a lot of useful information that can cover most of the broad strokes.

For the examples in this section, we're going to be looking at taking an HL7 v2.x ADT, and creating a FHIR Patient resource that represents the demographic information present in the message.

From the Patient documentation page, click on Mappings, and search for "HL7 v2". Or go directly to this link: http://hl7.org/fhir/R4/patient-mappings.html#v2

You will see that most of the FHIR resource properties have corresponding HL7 v2.x segment and field mappings. For example, the Patient.identifier property is mapped to the PID-3 field. But how exactly does each individual PID-3 component map into the identifier property?

Return to the Content tab, and look at the structure of the resource. You will see that the "identifier" property is of type Identifier.

Click on Identifier to navigate to the documentation page for that data type: http://hl7.org/fhir/R4/datatypes.html#Identifier. Then click on Mappings to view the HL7 v2.x mappings for that data type: http://hl7.org/fhir/R4/datatypes-mappings.html#Identifier

This should give you enough information to be able to map pieces of the HL7 message into the corresponding FHIR resource properties. To see how, read on...