Clinical information is typically expressed using some form of coded content and very often the FHIR datatype ‘CodeableConcept’ is used for this. “It is one of the most common patterns in healthcare data. A typical use of CodeableConcept is to send the local code that the concept was coded with, and also one or more translations to publicly defined code systems such as LOINC or SNOMED CT. Sending local codes is useful and important for the purposes of debugging and integrity auditing.” Equally important in this way, it is RECOMMENDED to add display values when sending codes.

Using UserSelected Boolean, it is possible to clarify which code was actually chosen by the user when multiple codes are sent. It is RECOMMENDED to use this Boolean.

Please note that although in some profiles only ‘0..1’ ‘CodeableConcept’ is mentioned in the structure, this datatype actually contains possibilities to use more codes to define one concept. Refer to the official HL7 specification for further examples.

Special remarks for KMEHR users:
In many KMEHR messages there is the need to describe one concept with multiple coding systems. In KMEHR this is done by using multiple <cd> elements. In a FHIR profile, it will be very common to find the datatype to use for this is the Codeable Concept.

Note there is no S=’LOCAL’ way in FHIR. A local system will be identified by its own unique URI.