WHO Digital Documentation of COVID-19 Certificates (DDCC)
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WHO Digital Documentation of COVID-19 Certificates (DDCC), published by WHO. This guide is not an authorized publication; it is the continuous build for version 1.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/WorldHealthOrganization/ddcc/tree/main and changes regularly. See the Directory of published versions

Resource Profile: DDCCProcedure - Detailed Descriptions

Draft as of 2025-03-10

Definitions for the DDCCProcedure resource profile.

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

0. Procedure
Definition

An action that is or was performed on or for a patient. This can be a physical intervention like an operation, or less invasive like long term services, counseling, or hypnotherapy.

ShortAn action that is being or was performed on a patient
Control0..*
Is Modifierfalse
Summaryfalse
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.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-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-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
2. Procedure.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
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. Procedure.extension
Definition

An Extension


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.

ShortExtensionAdditional 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.

Control10..*
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 Procedure.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 6. Procedure.extension:country
    Slice Namecountry
    Definition

    DDCC Country Of Event for Immunization

    ShortDDCC Country Of Event for Immunization
    Control1..1
    This element is affected by the following invariants: ele-1
    TypeExtension(DDCC Country Of Event for Immunization) (Extension Type: code)
    Is Modifierfalse
    Must Supporttrue
    LabelCountry of vaccination
    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())
    8. Procedure.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..*
    TypeExtension
    Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
    Summaryfalse
    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())
    10. Procedure.status
    Definition

    A code specifying the state of the procedure. Generally, this will be the in-progress or completed state.

    Shortpreparation | in-progress | not-done | on-hold | stopped | completed | entered-in-error | unknown
    Comments

    The "unknown" code is not to be used to convey other statuses. The "unknown" code should be used when one of the statuses applies, but the authoring system doesn't know the current state of the procedure.

    This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

    Control1..1
    BindingThe codes SHALL be taken from EventStatushttp://hl7.org/fhir/ValueSet/event-status|4.0.1
    (required to http://hl7.org/fhir/ValueSet/event-status|4.0.1)

    A code specifying the state of the procedure.

    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
    Summarytrue
    Fixed Valuecompleted
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    12. Procedure.code
    Definition

    Identification of the procedure or recording of "absence of relevant procedures" or of "procedures unknown".


    The specific procedure that is performed. Use text if the exact nature of the procedure cannot be coded (e.g. "Laparoscopic Appendectomy").

    ShortConcept - reference to a terminology or just textIdentification of the procedure
    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.

    Control10..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHOULD be taken from For example codes, see Procedures - SNOMED CT + Absent/Unknown - IPShttp://hl7.org/fhir/ValueSet/procedure-code
    (preferred to http://hl7.org/fhir/uv/ips/ValueSet/procedures-snomed-absent-unknown-uv-ips)

    SNOMED CT procedure code set or a code for absent/unknown procedure


    A code to identify a specific procedure .

    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalse
    Must Supporttrue
    Requirements

    0..1 to account for primarily narrative only resources.

    Alternate Namestype
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    14. Procedure.subject
    Definition

    The person on which the procedure was performed.


    The person, animal or group on which the procedure was performed.

    ShortWho the procedure was performed on
    Control1..1
    TypeReference(Patient (IPS), Patient, Group)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Alternate Namespatient
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    16. Procedure.subject.reference
    Definition

    A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

    ShortLiteral reference, Relative, internal or absolute URL
    Comments

    Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

    Control10..1
    This element is affected by the following invariants: ref-1
    Typestring
    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()))
    18. Procedure.performed[x]
    Definition

    Estimated or actual date, date-time, period, or age when the procedure was performed. Allows a period to support complex procedures that span more than one date, and also allows for the length of the procedure to be captured.

    ShortWhen the procedure was performed
    Comments

    Age is generally used when the patient reports an age at which the procedure was performed. Range is generally used when the patient reports an age range when the procedure was performed, such as sometime between 20-25 years old. dateTime supports a range of precision due to some procedures being reported as past procedures that might not have millisecond precision while other procedures performed and documented during the encounter might have more precise UTC timestamps with timezone.

    Control10..1
    TypedateTime, string, Period, Range, Age
    [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
    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()))
    20. Procedure.performed[x].extension:data-absent-reason
    Slice Namedata-absent-reason
    Definition

    Provides a reason why the performed is missing.

    Shortperformed[x] absence reason
    Control0..1
    TypeExtension(Data Absent Reason) (Extension Type: code)
    Is Modifierfalse
    Must Supporttrue
    Summaryfalse
    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())
    22. Procedure.location
    Definition

    The location where the procedure actually happened. E.g. a newborn at home, a tracheostomy at a restaurant.

    ShortWhere the procedure happened
    Control0..1
    TypeReference(Location)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Requirements

    Ties a procedure to where the records are likely kept.

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

    This could be a histology result, pathology report, surgical report, etc.

    ShortAny report resulting from the procedure
    Comments

    There could potentially be multiple reports - e.g. if this was a procedure which took multiple biopsies resulting in a number of anatomical pathology reports.

    Control10..1*
    TypeReference(DDCC Diagnostic Report, DiagnosticReport, DocumentReference, Composition)
    Is Modifierfalse
    Must Supporttrue
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    26. Procedure.usedReference
    Definition

    Identifies medications, devices and any other substance used as part of the procedure.

    ShortItems used during procedure
    Comments

    For devices actually implanted or removed, use Procedure.device.

    Control10..1*
    TypeReference(DDCC Test, Device, Medication, Substance)
    Is Modifierfalse
    Must Supporttrue
    Summaryfalse
    Requirements

    Used for tracking contamination, etc.

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