SGHI FHIR Profile Implementation Guide
0.1.0 - ci-build

SGHI FHIR Profile Implementation Guide, published by Kathurima Kimathi. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/savannahghi/sil_fhir_profile_ig/ and changes regularly. See the Directory of published versions

Data Type Profile: SGHICodeableConcept - Detailed Descriptions

Draft as of 2025-09-04

Definitions for the sghi-codeableconcept data type profile.

Guidance on how to interpret the contents of this table can be foundhere

0. CodeableConcept
Definition

A concept that may be defined by a formal reference to a terminology or ontology or may be provided by text.

ShortConcept - reference to a terminology or just text
Comments

Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination.

Control0..*
Is Modifierfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
2. CodeableConcept.coding
Definition

A reference to a code defined by a terminology system.

ShortCode defined by a terminology system
Comments

Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

Control10..*
TypeCoding
Is Modifierfalse
Summarytrue
Requirements

Allows for alternative encodings within a code system, and translations to other code systems.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. CodeableConcept.coding.system
Definition

The identification of the code system that defines the meaning of the symbol in the code.

ShortIdentity of the terminology system
Comments

The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should be an absolute reference to some definition that establishes the system clearly and unambiguously.

Control10..1
Typeuri
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Requirements

Need to be unambiguous about the source of the definition of the symbol.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
6. CodeableConcept.coding.code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

ShortSymbol in syntax defined by the system
Control10..1
This element is affected by the following invariants: cod-1
Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Requirements

Need to refer to a particular code in the system.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
8. CodeableConcept.coding.display
Definition

A representation of the meaning of the code in the system, following the rules of the system.

ShortRepresentation defined by the system
Control10..1
This element is affected by the following invariants: cod-1
Typestring
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Requirements

Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

Guidance on how to interpret the contents of this table can be foundhere

0. CodeableConcept
2. CodeableConcept.coding
Control1..?
4. CodeableConcept.coding.system
Control1..?
6. CodeableConcept.coding.code
Control1..?
8. CodeableConcept.coding.display
Control1..?

Guidance on how to interpret the contents of this table can be foundhere

0. CodeableConcept
Definition

A concept that may be defined by a formal reference to a terminology or ontology or may be provided by text.

ShortConcept - reference to a terminology or just text
Comments

Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination.

Control0..*
Is Modifierfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
2. CodeableConcept.id
Definition

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

ShortUnique id for inter-element referencing
Control0..1
This element is affected by the following invariants: ele-1
Typeid
Is Modifierfalse
XML FormatIn the XML format, this property is represented as an attribute.
Summaryfalse
4. CodeableConcept.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

ShortAdditional content defined by implementations
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifierfalse
Summaryfalse
Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
SlicingThis element introduces a set of slices on CodeableConcept.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 6. CodeableConcept.coding
    Definition

    A reference to a code defined by a terminology system.

    ShortCode defined by a terminology system
    Comments

    Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

    Control1..*
    TypeCoding
    Is Modifierfalse
    Summarytrue
    Requirements

    Allows for alternative encodings within a code system, and translations to other code systems.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    8. CodeableConcept.coding.id
    Definition

    Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

    ShortUnique id for inter-element referencing
    Control0..1
    This element is affected by the following invariants: ele-1
    Typeid
    Is Modifierfalse
    XML FormatIn the XML format, this property is represented as an attribute.
    Summaryfalse
    10. CodeableConcept.coding.extension
    Definition

    May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

    ShortAdditional content defined by implementations
    Comments

    There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

    Control0..*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Alternate Namesextensions, user content
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    SlicingThis element introduces a set of slices on CodeableConcept.coding.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 12. CodeableConcept.coding.system
      Definition

      The identification of the code system that defines the meaning of the symbol in the code.

      ShortIdentity of the terminology system
      Comments

      The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should be an absolute reference to some definition that establishes the system clearly and unambiguously.

      Control1..1
      Typeuri
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Requirements

      Need to be unambiguous about the source of the definition of the symbol.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      14. CodeableConcept.coding.version
      Definition

      The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

      ShortVersion of the system - if relevant
      Comments

      Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

      NoteThis is a business version Id, not a resource version Id (see discussion)
      Control0..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      16. CodeableConcept.coding.code
      Definition

      A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

      ShortSymbol in syntax defined by the system
      Control1..1
      This element is affected by the following invariants: cod-1
      Typecode
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Requirements

      Need to refer to a particular code in the system.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      18. CodeableConcept.coding.display
      Definition

      A representation of the meaning of the code in the system, following the rules of the system.

      ShortRepresentation defined by the system
      Control1..1
      This element is affected by the following invariants: cod-1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Requirements

      Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      20. CodeableConcept.coding.userSelected
      Definition

      Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).

      ShortIf this coding was chosen directly by the user
      Comments

      Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

      Control0..1
      Typeboolean
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Requirements

      This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      22. CodeableConcept.text
      Definition

      A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

      ShortPlain text representation of the concept
      Comments

      Very often the text is the same as a displayName of one of the codings.

      Control0..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Requirements

      The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))