# Concept (deprecated)

## Overview

Concept resource has a similar structure as Coding and [CodeSystem.concept](https://www.hl7.org/fhir/codesystem-definitions.html#CodeSystem.concept) element. When you upload code system into [Aidbox](https://www.health-samurai.io/aidbox), we split CodeSystem resource into concepts. But for your convenience CRUD operations are allowed as well on the Concept resource. To create and manage simple dictionary/terminology, you can create a set of Concepts using Create operation.

```yaml
resourceType: Concept
# id of concept; usually short name for terminology + code
id: loinc-17861-6
# inactivity flag
deprecated: true
system: http://loinc.org
code: 17861-6
display: Calcium [Mass/​volume] in Serum or Plasma	 
# pre-expanded list of valueset ids/urls
valueset:
- labs
definition: <Definition string>
hierarchy:
  - parent-code-1
  - parent-code-2
designation:
  display:
    ge: der Calcium
    es: el calcium
    ru: Кальций
  definition:
    ge: der Calcium
    es: el calcium
property:
   LOINC:
     long_common_name: ...
     relatednames2: ...
```

## Structure

### deprecated

This is a boolean flag, which can be used to deactivate (but not delete) a concept. This is the best-practice for terminology management - _never delete concepts, but deprecate_

### system

It's a symbolic link on CodeSystem

### ancestors

A new hierarchy element-object that contains ancestors codes and amount of hops between current concept and ancestor. [See](handling-hierarchies-using-ancestors.md) detailed description and use cases.

### hierarchy

A hierarchy element contains codes of parent concepts for hierarchical terminologies from top to bottom. This element is used for Subsumption Operation where you test that some code **isA** another code.

### designation

Designation element is copy semantic of [CodeSystem.concept.designation](https://www.hl7.org/fhir/codesystem-definitions.html#CodeSystem.concept.designation) - Additional representations for the concept - other languages, aliases, specialised purposes, used for particular purposes, etc. In Aidbox, it is represented in a more database-friendly format.&#x20;

In [CodeSystem.concept.designation](https://www.hl7.org/fhir/codesystem-definitions.html#CodeSystem.concept.designation) is a collection of complex elements:

```yaml
designation:
  - use:
      system: http://...designation-usage
      code: display
    language: ge
    value: eigenclass
  - use:
      system: http://...designation-usage
      code: display
    language: es
    value: el eigenclass
// to access it you need something like this
// designation.where(use='display' and language='ge').value
```

In Aidbox, it's grouped by _use.code_ and after that by l_anguage_ attributes:

```yaml
designation:
  display:
    ge: der Calcium
    es: el calcium
    ru: Кальций
  definition:
    ge: der Calcium
    es: el calcium
// much more easy with this format
// designation.display.ge
```

### property

{% hint style="warning" %}
Be careful, `Concept.property` is different from a FHIR `CodeSystem.concept.property`! Concept.property is just an arbitrary JSON object with custom properties. It is good practice to put these props under the unique CodeSystem key.
{% endhint %}

A property element is a polymorphic element, which contains additional properties for a concept like an axis of classification, etc. In Aidbox, we use a more database-oriented encoding with Object instead of the FHIR generic property array.

Example Concept with property:

```yaml
resourceType: Concept
system: http://loinc.org
code: 17861-6
...
property:
   LOINC:
     long_common_name: ...
     relatednames2: ...
```