LOINC could be considered as a ISO 11179 MDR (Metadata Registry) which includes various lab/clinical generic data elements.
Take openEHR Archetype Pulse/Heart beat as an example.
The root node could be considered as a ISO 11179 Object Class (i.e., Concept) ; the names of its Data Nodes/Points could be considered as ISO 11179 Properties; actually, such Data Nodes/Points are ISO 11179 Data Elements.
For example, the fully specified name of the Data Point “Rate” should be “Pulse Rate/Heart Beat Rate” and this Data Element has a non-enumerated Value Domain as followings:
It’s my current understanding related to this topic.
However, the Archetype Pulse/Heart beat per se looks like a Data Set Specification (a structured set of Data Elements) other than an Object Class. Here, consider Pulse Rate. The Object Classes should be Its Concept Name “Pulse/Heart beat” and the Property should be its Data Point name “Rate”…
Note: Illustration of Data Element and Dataset Specifications taken from AIHW’s METEOR
But when searching LOINC codes with keywords “pulse rate NRat”, there are 64 codes for potential matches returned. As we know, for the sake of generality, the Archetype is not designed with fixed values for some LOINC Axes such as Timing, System and Method, so it is impossible to map an openEHR Archetype Data Point to the exact matching LOINC code at the Archetype level but a set of potentially matching LOINC codes (i.e., a Value Domain or FHIR ValueSet). So, we may need to defer the exact LOINC mapping to the template level.