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

Resource Profile: Composition - Detailed Descriptions

Draft as of 2024-11-06

Definitions for the Composition resource profile.

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

0. Composition

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

0. Composition
Definition

A set of healthcare-related information that is assembled together into a single logical package that provides a single coherent statement of meaning, establishes its own context and that has clinical attestation with regard to who is making the statement. A Composition defines the structure and narrative content necessary for a document. However, a Composition alone does not constitute a document. Rather, the Composition SHALL be the first entry in a Bundle where Bundle.type=document, and any other resources referenced from Composition SHALL be included as subsequent entries in the Bundle, for example Patient, Practitioner, Encounter, etc.


A set of healthcare-related information that is assembled together into a single logical package that provides a single coherent statement of meaning, establishes its own context and that has clinical attestation with regard to who is making the statement. A Composition defines the structure and narrative content necessary for a document. However, a Composition alone does not constitute a document. Rather, the Composition must be the first entry in a Bundle where Bundle.type=document, and any other resources referenced from Composition must be included as subsequent entries in the Bundle (for example Patient, Practitioner, Encounter, etc.).

ShortA set of resources composed into a single coherent clinical statement with clinical attestation
Comments

While the focus of this specification is on patient-specific clinical statements, this resource can also apply to other healthcare-related statements such as study protocol designs, healthcare invoices and other activities that are not necessarily patient-specific or clinical.

Control0..*
Is Modifierfalse
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
2. Composition.implicitRules
Definition

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

ShortA set of rules under which this content was created
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

Control0..1
This element is affected by the following invariants: ele-1
Typeuri
Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
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()))
4. Composition.extension:careSettingType
Slice NamecareSettingType
Definition

The type of care setting associated with a composition or a list.

ShortThe type of care setting associated with a composition or a list.
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..1
This element is affected by the following invariants: ele-1
TypeExtension(Extension UK Core Care Setting Type) (Extension Type: CodeableConcept)
Standard StatusNormative (from Trial Use)
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())
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
6. Composition.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

ShortExtensions that cannot be ignored
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..*
This element is affected by the following invariants: ele-1
TypeExtension
Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Standard StatusNormative (from Trial Use)
Requirements

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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())
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Composition.modifierExtension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 8. Composition.status
    Definition

    The workflow/clinical status of this composition. The status is a marker for the clinical standing of the document.

    Shortpreliminary | final | amended | entered-in-error
    Comments

    If a composition is marked as withdrawn, the compositions/documents in the series, or data from the composition or document series, should never be displayed to a user without being clearly marked as untrustworthy. The flag "entered-in-error" is why this element is labeled as a modifier of other elements.

    Some reporting work flows require that the original narrative of a final document never be altered; instead, only new narrative can be added. The composition resource has no explicit status for explicitly noting whether this business rule is in effect. This would be handled by an extension if required.

    Control1..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHALL be taken from CompositionStatushttp://hl7.org/fhir/ValueSet/composition-status|4.0.1
    (required to http://hl7.org/fhir/ValueSet/composition-status|4.0.1)

    The workflow/clinical status of the composition.

    Typecode
    Is Modifiertrue because This element is labelled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

    Need to be able to mark interim, amended, or withdrawn compositions or documents.

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

    Specifies the particular kind of composition (e.g. History and Physical, Discharge Summary, Progress Note). This usually equates to the purpose of making the composition.

    ShortKind of composition (SNOMED CT)Kind of composition (LOINC if possible)
    Comments

    For Composition type, LOINC is ubiquitous and strongly endorsed by HL7. Most implementation guides will require a specific LOINC code, or use LOINC as an extensible binding.

    Control1..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHOULD be taken from UK Core Document Typehttp://hl7.org/fhir/ValueSet/doc-typecodes
    (preferred to https://fhir.hl7.org.uk/ValueSet/UKCore-DocumentType)

    SNOMED CT Document Type


    Type of a composition.

    TypeCodeableConcept
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Requirements

    Key metadata element describing the composition, used in searching/filtering.

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

    Who or what the composition is about. The composition can be about a person, (patient or healthcare practitioner), a device (e.g. a machine) or even a group of subjects (such as a document about a herd of livestock, or a set of patients that share a common exposure).

    ShortWho and/or what the composition is about
    Comments

    For clinical documents, this is usually the patient.

    Control0..1
    This element is affected by the following invariants: ele-1
    TypeReference(Resource)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Requirements

    Essential metadata for searching for the composition. Identifies who and/or what the composition/document is about.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
    14. Composition.date
    Definition

    The composition editing time, when the composition was last logically changed by the author.

    ShortComposition editing time
    Comments

    The Last Modified Date on the composition may be after the date of the document was attested without being changed.

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

    dateTime is used for tracking, organizing versions and searching. Note that this is the time of authoring. When packaged in a document, Bundle.timestamp is the date of packaging.


    dateTime is used for tracking, organizing versions and searching. Note that this is the time of authoring. When packaged in a document, Bundle.timestamp is the date of packaging.

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

    Identifies who is responsible for the information in the composition, not necessarily who typed it in.

    ShortWho and/or what authored the composition
    Comments

    References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

    Control1..*
    This element is affected by the following invariants: ele-1
    TypeReference(Practitioner, PractitionerRole, Device, Patient, RelatedPerson, Organization)
    Is Modifierfalse
    Must Supporttrue
    Must Support TypesNo must-support rules about the choice of types/profiles
    Summarytrue
    Requirements

    Identifies who is responsible for the content.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
    18. Composition.title
    Definition

    Official human-readable label for the composition.

    ShortHuman Readable name/title
    Comments

    For many compositions, the title is the same as the text or a display name of Composition.type (e.g. a "consultation" or "progress note"). Note that CDA does not make title mandatory, but there are no known cases where it is useful for title to be omitted, so it is mandatory here. Feedback on this requirement is welcome during the trial use period.

    Control1..1
    This element is affected by the following invariants: ele-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()))
    20. Composition.confidentiality
    Definition

    The code specifying the level of confidentiality of the Composition.

    ShortAs defined by affinity domain
    Comments

    The exact use of this element, and enforcement and issues related to highly sensitive documents are out of scope for the base specification, and delegated to implementation profiles (see security section). This element is labeled as a modifier because highly confidential documents must not be treated as if they are not.

    Control0..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHALL be taken from v3.ConfidentialityClassification (2014-03-26)http://terminology.hl7.org/ValueSet/v3-ConfidentialityClassification|2014-03-26
    (required to http://terminology.hl7.org/ValueSet/v3-ConfidentialityClassification|2014-03-26)

    Codes specifying the level of confidentiality of the composition.

    Typecode
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    22. Composition.custodian
    Definition

    Identifies the organization or group who is responsible for ongoing maintenance of and access to the composition/document information.

    ShortOrganization which maintains the composition
    Comments

    This is useful when documents are derived from a composition - provides guidance for how to get the latest version of the document. This is optional because this is sometimes not known by the authoring system, and can be inferred by context. However, it is important that this information be known when working with a derived document, so providing a custodian is encouraged.

    Control0..1
    This element is affected by the following invariants: ele-1
    TypeReference(Organization)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Requirements

    Identifies where to go to find the current version, where to report issues, etc.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))

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

    0. Composition
    Definition

    A set of healthcare-related information that is assembled together into a single logical package that provides a single coherent statement of meaning, establishes its own context and that has clinical attestation with regard to who is making the statement. A Composition defines the structure and narrative content necessary for a document. However, a Composition alone does not constitute a document. Rather, the Composition SHALL be the first entry in a Bundle where Bundle.type=document, and any other resources referenced from Composition SHALL be included as subsequent entries in the Bundle, for example Patient, Practitioner, Encounter, etc.

    ShortA set of resources composed into a single coherent clinical statement with clinical attestation
    Comments

    While the focus of this specification is on patient-specific clinical statements, this resource can also apply to other healthcare-related statements such as study protocol designs, healthcare invoices and other activities that are not necessarily patient-specific or clinical.

    Control0..*
    Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
    dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
    dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
    dom-6: A resource should have narrative for robust management (text.`div`.exists())
    dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
    2. Composition.id
    Definition

    The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

    ShortLogical id of this artifact
    Comments

    The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

    Control0..1
    Typeid
    Summarytrue
    4. Composition.meta
    Definition

    The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

    ShortMetadata about the resource
    Control0..1
    This element is affected by the following invariants: ele-1
    TypeMeta
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    6. Composition.implicitRules
    Definition

    A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

    ShortA set of rules under which this content was created
    Comments

    Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

    Control0..1
    This element is affected by the following invariants: ele-1
    Typeuri
    Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
    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()))
    8. Composition.language
    Definition

    The base language in which the resource is written.

    ShortLanguage of the resource content
    Comments

    Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

    Control0..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHOULD be taken from CommonLanguages
    (preferred to http://hl7.org/fhir/ValueSet/languages)

    A human language.

    Additional BindingsPurpose
    AllLanguagesMax Binding
    Typecode
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    10. Composition.text
    Definition

    A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

    ShortText summary of the resource, for human interpretation
    Comments

    Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

    Control0..1
    This element is affected by the following invariants: ele-1
    TypeNarrative
    Alternate Namesnarrative, html, xhtml, display
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    12. Composition.contained
    Definition

    These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

    ShortContained, inline Resources
    Comments

    This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags In their meta elements, but SHALL NOT have security labels.

    Control0..*
    TypeResource
    Alternate Namesinline resources, anonymous resources, contained resources
    14. Composition.extension
    Definition

    May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, 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..*
    This element is affected by the following invariants: ele-1
    TypeExtension
    Standard StatusNormative (from Trial Use)
    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 Composition.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 16. Composition.extension:careSettingType
      Slice NamecareSettingType
      Definition

      The type of care setting associated with a composition or a list.

      ShortThe type of care setting associated with a composition or a list.
      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..1
      This element is affected by the following invariants: ele-1
      TypeExtension(Extension UK Core Care Setting Type) (Extension Type: CodeableConcept)
      Standard StatusNormative (from Trial Use)
      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())
      18. Composition.modifierExtension
      Definition

      May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

      Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

      ShortExtensions that cannot be ignored
      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..*
      This element is affected by the following invariants: ele-1
      TypeExtension
      Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
      Standard StatusNormative (from Trial Use)
      Requirements

      Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

      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 Composition.modifierExtension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 20. Composition.identifier
        Definition

        A version-independent identifier for the Composition. This identifier stays constant as the composition is changed over time.

        ShortVersion-independent identifier for the Composition
        Comments

        Similar to ClinicalDocument/setId in CDA. See discussion in resource definition for how these relate.

        NoteThis is a business identifier, not a resource identifier (see discussion)
        Control0..1
        This element is affected by the following invariants: ele-1
        TypeIdentifier
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        22. Composition.status
        Definition

        The workflow/clinical status of this composition. The status is a marker for the clinical standing of the document.

        Shortpreliminary | final | amended | entered-in-error
        Comments

        If a composition is marked as withdrawn, the compositions/documents in the series, or data from the composition or document series, should never be displayed to a user without being clearly marked as untrustworthy. The flag "entered-in-error" is why this element is labeled as a modifier of other elements.

        Some reporting work flows require that the original narrative of a final document never be altered; instead, only new narrative can be added. The composition resource has no explicit status for explicitly noting whether this business rule is in effect. This would be handled by an extension if required.

        Control1..1
        This element is affected by the following invariants: ele-1
        BindingThe codes SHALL be taken from CompositionStatus
        (required to http://hl7.org/fhir/ValueSet/composition-status|4.0.1)

        The workflow/clinical status of the composition.

        Typecode
        Is Modifiertrue because This element is labelled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Must Supporttrue
        Summarytrue
        Requirements

        Need to be able to mark interim, amended, or withdrawn compositions or documents.

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

        Specifies the particular kind of composition (e.g. History and Physical, Discharge Summary, Progress Note). This usually equates to the purpose of making the composition.

        ShortKind of composition (SNOMED CT)
        Comments

        For Composition type, LOINC is ubiquitous and strongly endorsed by HL7. Most implementation guides will require a specific LOINC code, or use LOINC as an extensible binding.

        Control1..1
        This element is affected by the following invariants: ele-1
        BindingThe codes SHOULD be taken from UK Core Document Type
        (preferred to https://fhir.hl7.org.uk/ValueSet/UKCore-DocumentType)

        SNOMED CT Document Type

        TypeCodeableConcept
        Must Supporttrue
        Summarytrue
        Requirements

        Key metadata element describing the composition, used in searching/filtering.

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

        A categorization for the type of the composition - helps for indexing and searching. This may be implied by or derived from the code specified in the Composition Type.

        ShortCategorization of Composition
        Comments

        This is a metadata field from XDS/MHD.

        Control0..*
        This element is affected by the following invariants: ele-1
        BindingThe codes SHOULD be taken from UK Core Composition Category
        (preferred to https://fhir.hl7.org.uk/ValueSet/UKCore-CompositionCategory)

        A ValueSet to identify the category of a composition.

        TypeCodeableConcept
        Summarytrue
        Requirements

        Helps humans to assess whether the composition is of interest when viewing an index of compositions or documents.

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

        Who or what the composition is about. The composition can be about a person, (patient or healthcare practitioner), a device (e.g. a machine) or even a group of subjects (such as a document about a herd of livestock, or a set of patients that share a common exposure).

        ShortWho and/or what the composition is about
        Comments

        For clinical documents, this is usually the patient.

        Control0..1
        This element is affected by the following invariants: ele-1
        TypeReference(Resource)
        Must Supporttrue
        Summarytrue
        Requirements

        Essential metadata for searching for the composition. Identifies who and/or what the composition/document is about.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
        30. Composition.encounter
        Definition

        Describes the clinical encounter or type of care this documentation is associated with.

        ShortContext of the Composition
        Comments

        References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

        Control0..1
        This element is affected by the following invariants: ele-1
        TypeReference(Encounter)
        Summarytrue
        Requirements

        Provides context for the composition and supports searching.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
        32. Composition.date
        Definition

        The composition editing time, when the composition was last logically changed by the author.

        ShortComposition editing time
        Comments

        The Last Modified Date on the composition may be after the date of the document was attested without being changed.

        Control1..1
        This element is affected by the following invariants: ele-1
        TypedateTime
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summarytrue
        Requirements

        dateTime is used for tracking, organizing versions and searching. Note that this is the time of authoring. When packaged in a document, Bundle.timestamp is the date of packaging.

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

        Identifies who is responsible for the information in the composition, not necessarily who typed it in.

        ShortWho and/or what authored the composition
        Comments

        References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

        Control1..*
        This element is affected by the following invariants: ele-1
        TypeReference(Practitioner, PractitionerRole, Device, Patient, RelatedPerson, Organization)
        Must Supporttrue
        Must Support TypesNo must-support rules about the choice of types/profiles
        Summarytrue
        Requirements

        Identifies who is responsible for the content.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
        36. Composition.title
        Definition

        Official human-readable label for the composition.

        ShortHuman Readable name/title
        Comments

        For many compositions, the title is the same as the text or a display name of Composition.type (e.g. a "consultation" or "progress note"). Note that CDA does not make title mandatory, but there are no known cases where it is useful for title to be omitted, so it is mandatory here. Feedback on this requirement is welcome during the trial use period.

        Control1..1
        This element is affected by the following invariants: ele-1
        Typestring
        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()))
        38. Composition.confidentiality
        Definition

        The code specifying the level of confidentiality of the Composition.

        ShortAs defined by affinity domain
        Comments

        The exact use of this element, and enforcement and issues related to highly sensitive documents are out of scope for the base specification, and delegated to implementation profiles (see security section). This element is labeled as a modifier because highly confidential documents must not be treated as if they are not.

        Control0..1
        This element is affected by the following invariants: ele-1
        BindingThe codes SHALL be taken from v3.ConfidentialityClassification (2014-03-26)
        (required to http://terminology.hl7.org/ValueSet/v3-ConfidentialityClassification|2014-03-26)

        Codes specifying the level of confidentiality of the composition.

        Typecode
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Must Supporttrue
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        40. Composition.attester
        Definition

        A participant who has attested to the accuracy of the composition/document.

        ShortAttests to accuracy of composition
        Comments

        Only list each attester once.

        Control0..*
        This element is affected by the following invariants: ele-1
        TypeBackboneElement
        Requirements

        Identifies responsibility for the accuracy of the composition content.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        42. Composition.attester.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
        Typestring
        XML FormatIn the XML format, this property is represented as an attribute.
        44. Composition.attester.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 manageable, 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..*
        This element is affected by the following invariants: ele-1
        TypeExtension
        Standard StatusNormative (from Trial Use)
        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 Composition.attester.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ url
        • 46. Composition.attester.modifierExtension
          Definition

          May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, 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. Applications processing a resource are required to check for modifier extensions.

          Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

          ShortExtensions that cannot be ignored even if unrecognized
          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..*
          This element is affected by the following invariants: ele-1
          TypeExtension
          Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
          Summarytrue
          Requirements

          Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

          Alternate Namesextensions, user content, modifiers
          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())
          48. Composition.attester.mode
          Definition

          The type of attestation the authenticator offers.

          Shortpersonal | professional | legal | official
          Comments

          Note that FHIR strings SHALL NOT exceed 1MB in size

          Control1..1
          This element is affected by the following invariants: ele-1
          BindingThe codes SHALL be taken from CompositionAttestationMode
          (required to http://hl7.org/fhir/ValueSet/composition-attestation-mode|4.0.1)

          The way in which a person authenticated a composition.

          Typecode
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Requirements

          Indicates the level of authority of the attestation.

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

          When the composition was attested by the party.

          ShortWhen the composition was attested
          Control0..1
          This element is affected by the following invariants: ele-1
          TypedateTime
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Requirements

          Identifies when the information in the composition was deemed accurate. (Things may have changed since then.).

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

          Who attested the composition in the specified way.

          ShortWho attested the composition
          Comments

          References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

          Control0..1
          This element is affected by the following invariants: ele-1
          TypeReference(Patient, RelatedPerson, Practitioner, PractitionerRole, Organization)
          Requirements

          Identifies who has taken on the responsibility for accuracy of the composition content.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
          54. Composition.custodian
          Definition

          Identifies the organization or group who is responsible for ongoing maintenance of and access to the composition/document information.

          ShortOrganization which maintains the composition
          Comments

          This is useful when documents are derived from a composition - provides guidance for how to get the latest version of the document. This is optional because this is sometimes not known by the authoring system, and can be inferred by context. However, it is important that this information be known when working with a derived document, so providing a custodian is encouraged.

          Control0..1
          This element is affected by the following invariants: ele-1
          TypeReference(Organization)
          Must Supporttrue
          Summarytrue
          Requirements

          Identifies where to go to find the current version, where to report issues, etc.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
          56. Composition.relatesTo
          Definition

          Relationships that this composition has with other compositions or documents that already exist.

          ShortRelationships to other compositions/documents
          Comments

          A document is a version specific composition.

          Control0..*
          This element is affected by the following invariants: ele-1
          TypeBackboneElement
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          58. Composition.relatesTo.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
          Typestring
          XML FormatIn the XML format, this property is represented as an attribute.
          60. Composition.relatesTo.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 manageable, 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..*
          This element is affected by the following invariants: ele-1
          TypeExtension
          Standard StatusNormative (from Trial Use)
          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 Composition.relatesTo.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
          • value @ url
          • 62. Composition.relatesTo.modifierExtension
            Definition

            May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, 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. Applications processing a resource are required to check for modifier extensions.

            Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

            ShortExtensions that cannot be ignored even if unrecognized
            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..*
            This element is affected by the following invariants: ele-1
            TypeExtension
            Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
            Summarytrue
            Requirements

            Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

            Alternate Namesextensions, user content, modifiers
            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())
            64. Composition.relatesTo.code
            Definition

            The type of relationship that this composition has with anther composition or document.

            Shortreplaces | transforms | signs | appends
            Comments

            If this document appends another document, then the document cannot be fully understood without also accessing the referenced document.

            Control1..1
            This element is affected by the following invariants: ele-1
            BindingThe codes SHALL be taken from DocumentRelationshipType
            (required to http://hl7.org/fhir/ValueSet/document-relationship-type|4.0.1)

            The type of relationship between documents.

            Typecode
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            66. Composition.relatesTo.target[x]
            Definition

            The target composition/document of this relationship.

            ShortTarget of the relationship
            Control1..1
            This element is affected by the following invariants: ele-1
            TypeChoice of: Identifier, Reference(Composition)
            [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            68. Composition.event
            Definition

            The clinical service, such as a colonoscopy or an appendectomy, being documented.

            ShortThe clinical service(s) being documented
            Comments

            The event needs to be consistent with the type element, though can provide further information if desired.

            Control0..*
            This element is affected by the following invariants: ele-1
            TypeBackboneElement
            Summarytrue
            Requirements

            Provides context for the composition and creates a linkage between a resource describing an event and the composition created describing the event.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            70. Composition.event.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
            Typestring
            XML FormatIn the XML format, this property is represented as an attribute.
            72. Composition.event.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 manageable, 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..*
            This element is affected by the following invariants: ele-1
            TypeExtension
            Standard StatusNormative (from Trial Use)
            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 Composition.event.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
            • value @ url
            • 74. Composition.event.modifierExtension
              Definition

              May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, 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. Applications processing a resource are required to check for modifier extensions.

              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

              ShortExtensions that cannot be ignored even if unrecognized
              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..*
              This element is affected by the following invariants: ele-1
              TypeExtension
              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
              Summarytrue
              Requirements

              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

              Alternate Namesextensions, user content, modifiers
              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())
              76. Composition.event.code
              Definition

              This list of codes represents the main clinical acts, such as a colonoscopy or an appendectomy, being documented. In some cases, the event is inherent in the typeCode, such as a "History and Physical Report" in which the procedure being documented is necessarily a "History and Physical" act.

              ShortCode(s) that apply to the event being documented
              Comments

              An event can further specialize the act inherent in the typeCode, such as where it is simply "Procedure Report" and the procedure was a "colonoscopy". If one or more eventCodes are included, they SHALL NOT conflict with the values inherent in the classCode, practiceSettingCode or typeCode, as such a conflict would create an ambiguous situation. This short list of codes is provided to be used as key words for certain types of queries.

              Control0..*
              This element is affected by the following invariants: ele-1
              BindingFor example codes, see v3 Code System ActCode
              (example to http://terminology.hl7.org/ValueSet/v3-ActCode)

              This list of codes represents the main clinical acts being documented.

              TypeCodeableConcept
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              78. Composition.event.period
              Definition

              The period of time covered by the documentation. There is no assertion that the documentation is a complete representation for this period, only that it documents events during this time.

              ShortThe period covered by the documentation
              Comments

              A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times").

              Period is not used for a duration (a measure of elapsed time). See Duration.

              Control0..1
              This element is affected by the following invariants: ele-1
              TypePeriod
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              per-1: If present, start SHALL have a lower value than end (start.hasValue().not() or end.hasValue().not() or (start <= end))
              80. Composition.event.detail
              Definition

              The description and/or reference of the event(s) being documented. For example, this could be used to document such a colonoscopy or an appendectomy.

              ShortThe event(s) being documented
              Comments

              References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

              Control0..*
              This element is affected by the following invariants: ele-1
              TypeReference(Resource)
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
              82. Composition.section
              Definition

              The root of the sections that make up the composition.

              ShortComposition is broken into sections
              Control0..*
              This element is affected by the following invariants: ele-1
              TypeBackboneElement
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              cmp-1: A section must contain at least one of text, entries, or sub-sections (text.exists() or entry.exists() or section.exists())
              cmp-2: A section can only have an emptyReason if it is empty (emptyReason.empty() or entry.empty())
              84. Composition.section.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
              Typestring
              XML FormatIn the XML format, this property is represented as an attribute.
              86. Composition.section.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 manageable, 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..*
              This element is affected by the following invariants: ele-1
              TypeExtension
              Standard StatusNormative (from Trial Use)
              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 Composition.section.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
              • value @ url
              • 88. Composition.section.modifierExtension
                Definition

                May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, 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. Applications processing a resource are required to check for modifier extensions.

                Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

                ShortExtensions that cannot be ignored even if unrecognized
                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..*
                This element is affected by the following invariants: ele-1
                TypeExtension
                Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
                Summarytrue
                Requirements

                Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

                Alternate Namesextensions, user content, modifiers
                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())
                90. Composition.section.title
                Definition

                The label for this particular section. This will be part of the rendered content for the document, and is often used to build a table of contents.

                ShortLabel for section (e.g. for ToC)
                Comments

                The title identifies the section for a human reader. The title must be consistent with the narrative of the resource that is the target of the section.content reference. Generally, sections SHOULD have titles, but in some documents, it is unnecessary or inappropriate. Typically, this is where a section has subsections that have their own adequately distinguishing title, or documents that only have a single section. Most Implementation Guides will make section title to be a required element.

                Control0..1
                This element is affected by the following invariants: ele-1
                Typestring
                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                Requirements

                Section headings are often standardized for different types of documents. They give guidance to humans on how the document is organized.

                Alternate Namesheader, label, caption
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                92. Composition.section.code
                Definition

                A code identifying the kind of content contained within the section. This must be consistent with the section title.

                ShortClassification of section (recommended)
                Comments

                The code identifies the section for an automated processor of the document. This is particularly relevant when using profiles to control the structure of the document.

                If the section has content (instead of sub-sections), the section.code does not change the meaning or interpretation of the resource that is the content of the section in the comments for the section.code.

                Control0..1
                This element is affected by the following invariants: ele-1
                BindingUnless not suitable, these codes SHALL be taken from UK Core Composition Section Code
                (extensible to https://fhir.hl7.org.uk/ValueSet/UKCore-CompositionSectionCode)

                Classification of a section of a composition/document.

                TypeCodeableConcept
                Requirements

                Provides computable standardized labels to topics within the document.

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

                Identifies who is responsible for the information in this section, not necessarily who typed it in.

                ShortWho and/or what authored the section
                Comments

                References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

                Control0..*
                This element is affected by the following invariants: ele-1
                TypeReference(Practitioner, PractitionerRole, Device, Patient, RelatedPerson, Organization)
                Requirements

                Identifies who is responsible for the content.

                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
                96. Composition.section.focus
                Definition

                The actual focus of the section when it is not the subject of the composition, but instead represents something or someone associated with the subject such as (for a patient subject) a spouse, parent, fetus, or donor. If not focus is specified, the focus is assumed to be focus of the parent section, or, for a section in the Composition itself, the subject of the composition. Sections with a focus SHALL only include resources where the logical subject (patient, subject, focus, etc.) matches the section focus, or the resources have no logical subject (few resources).

                ShortWho/what the section is about, when it is not about the subject of composition
                Comments

                Typically, sections in a doument are about the subject of the document, whether that is a patient, or group of patients, location, or device, or whatever. For some kind of documents, some sections actually contain data about related entities. Typical examples are a section in a newborn discharge summary concerning the mother, or family history documents, with a section about each family member, though there are many other examples.

                Control0..1
                This element is affected by the following invariants: ele-1
                TypeReference(Resource)
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
                98. Composition.section.text
                Definition

                A human-readable narrative that contains the attested content of the section, used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative.

                ShortText summary of the section, for human interpretation
                Comments

                Document profiles may define what content should be represented in the narrative to ensure clinical safety.

                Control0..1
                This element is affected by the following invariants: ele-1, cmp-1
                TypeNarrative
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                100. Composition.section.mode
                Definition

                How the entry list was prepared - whether it is a working list that is suitable for being maintained on an ongoing basis, or if it represents a snapshot of a list of items from another source, or whether it is a prepared list where items may be marked as added, modified or deleted.

                Shortworking | snapshot | changes
                Comments

                This element is labeled as a modifier because a change list must not be misunderstood as a complete list.

                Control0..1
                This element is affected by the following invariants: ele-1
                BindingThe codes SHALL be taken from ListMode
                (required to http://hl7.org/fhir/ValueSet/list-mode|4.0.1)

                The processing mode that applies to this section.

                Typecode
                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                Requirements

                Sections are used in various ways, and it must be known in what way it is safe to use the entries in them.

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

                Specifies the order applied to the items in the section entries.

                ShortOrder of section entries
                Comments

                Applications SHOULD render ordered lists in the order provided, but MAY allow users to re-order based on their own preferences as well. If there is no order specified, the order is unknown, though there may still be some order.

                Control0..1
                This element is affected by the following invariants: ele-1
                BindingThe codes SHOULD be taken from ListOrderCodes
                (preferred to http://hl7.org/fhir/ValueSet/list-order)

                What order applies to the items in the entry.

                TypeCodeableConcept
                Requirements

                Important for presentation and rendering. Lists may be sorted to place more important information first or to group related entries.

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

                A reference to the actual resource from which the narrative in the section is derived.

                ShortA reference to data that supports this section
                Comments

                If there are no entries in the list, an emptyReason SHOULD be provided.

                Control0..*
                This element is affected by the following invariants: ele-1, cmp-2
                TypeReference(Resource)
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
                106. Composition.section.emptyReason
                Definition

                If the section is empty, why the list is empty. An empty section typically has some text explaining the empty reason.

                ShortWhy the section is empty
                Comments

                The various reasons for an empty section make a significant interpretation to its interpretation. Note that this code is for use when the entire section content has been suppressed, and not for when individual items are omitted - implementers may consider using a text note or a flag on an entry in these cases.

                Control0..1
                This element is affected by the following invariants: ele-1, cmp-2
                BindingThe codes SHOULD be taken from ListEmptyReasons
                (preferred to http://hl7.org/fhir/ValueSet/list-empty-reason)

                If a section is empty, why it is empty.

                TypeCodeableConcept
                Requirements

                Allows capturing things like "none exist" or "not asked" which can be important for most lists.

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

                A nested sub-section within this section.

                ShortNested Section
                Comments

                Nested sections are primarily used to help human readers navigate to particular portions of the document.

                Control0..*
                This element is affected by the following invariants: cmp-1
                TypeSeettp://hl7.org/fhir/StructureDefinition/Composition#Composition.section