Concept Mapping Changes

Owned by Uthpala Pitawela
Jul 06, 2020
3 min read

A concept is a medical term or OpenMRS dictionary term that describes a thing in our world. It can be something used to describe a disease or procedure, or it could be something like a question that has an answer. The answers to the question can also be concepts. In general, things like numeric results or strings of characters are not themselves concepts. Refer to Concept Term under Concept Term and Mappings for more information. 

A concept map connects one concept to another concept. The concepts being mapped to can be other concepts within an OpenMRS concept dictionary, or they can be external concepts referenced by an outside entity. In the latter case, these are called reference terms. Reference terms usually have a code system (or source) and a numeric or alphanumeric identifier (or code). 

Concepts can be mapped to other concepts with a mapping relationship type. It is important to understand that the relationship between concepts can mean the concepts are exactly the same (just with different sources and codes) or that they are somehow related to one another. Concepts that are exactly the same in the entirety of their meaning are mapped with a “SAME-AS” relationship. Concepts that have more specificity than another (Stage 4 Breast Cancer versus just Breast Cancer) are mapped “NARROWER-THAN”. 

The default OpenMRS relationship types are:

  • SAME-AS
  • NARROWER-THAN
  • BROADER-THAN
  • Associated finding
  • Associated morphology
  • Associated procedure
  • Associated with
  • Causative agent
  • Finding site
  • Has specimen
  • Laterality
  • Severity

These are mapped to SNOMED CT concepts for relationship types, but there can be other relationship types. An explanation for each of these map types goes beyond this document but can be referenced externally. The relationship between source/code pairs and the OpenMRS concepts are deterministic. There should only be ONE and ONLY ONE map between an active OpenMRS concept and a source/code with a mapping type of SAME_AS (because having more than one OpenMRS concept mapped SAME_AS would imply that they are identical and would be duplicates). It is possible that multiple OpenMRS concepts could map to the same source/code pair if the mapping type is not SAME_AS. 

For example, maps between OpenMRS concepts and an administrative coding system like ICD-10-WHO will frequently be NARROWER-THAN. There will be multiple examples of more specific clinical concepts in OpenMRS that would appropriately map to a single ICD-10-WHO code. The ICD-10-WHO code D64.9 “Anemia, unspecified” is the correct ICD-10 code for multiple concepts in the CIEL dictionary: “Anemia”, “Severe anemia”, “Chronic anemia”, etc. The “unspecified” in the ICD code implies the cause of the anemia which is unspecified for the three examples. The mapping relationship between the OpenMRS term “Anemia” and the D64.9 code is SAME_AS (of note, the mapping between Anemia and Anemia, unspecified as SAME_AS is pragmatic). The relationship between the other OpenMRS anemia terms and the D64.9 code is NARROWER-THAN.

To add a map to an existing OpenMRS concept, edit the concept. The edit screen includes a section for mapping that looks like:

Note that there are separate columns for Relationship, Source, Code, and Name. To add a new concept map, click the Add Mapping button. You do NOT need to create the reference term in advance, as the UI will do so automatically. However, if you want to create the reference term in advance, you can click on the Create New Term button.

Doing so, a new line is appended to the end of the list of mappings with the default relationship of SAME-AS. Selecting a source and then starting to type will lookup existing codes for the selected source. If the code does not match an existing source code, then a new reference code will be created when the concept is saved. The Name field is optional.

Once the concept is saved, the new concept map will appear in the list of mappings such as that shown below.

Managing Relationship Types for concept and reference term maps and more information refer Standard and Non-standard Terminology Mapping.