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

0. Condition
Definition

A clinical condition, problem, diagnosis, or other event, situation, issue, or clinical concept that has risen to a level of concern.

ShortDocumentation of a health problem of the patientDetailed information about conditions, problems or diagnoses
Control0..*
Is Modifierfalse
Summaryfalse
Invariantscon-3: Condition.clinicalStatus SHALL be present if verificationStatus is not entered-in-error and category is problem-list-item (clinicalStatus.exists() or verificationStatus.coding.where(system='http://terminology.hl7.org/CodeSystem/condition-ver-status' and code = 'entered-in-error').exists() or category.select($this='problem-list-item').empty())
con-4: If condition is abated, then clinicalStatus must be either inactive, resolved, or remission (abatement.empty() or clinicalStatus.coding.where(system='http://terminology.hl7.org/CodeSystem/condition-clinical' and (code='resolved' or code='remission' or code='inactive')).exists())
con-5: Condition.clinicalStatus SHALL NOT be present if verification Status is entered-in-error (verificationStatus.coding.where(system='http://terminology.hl7.org/CodeSystem/condition-ver-status' and code='entered-in-error').empty() or clinicalStatus.empty())
dom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
con-3: Condition.clinicalStatus SHALL be present if verificationStatus is not entered-in-error and category is problem-list-item (clinicalStatus.exists() or verificationStatus.coding.where(system='http://terminology.hl7.org/CodeSystem/condition-ver-status' and code = 'entered-in-error').exists() or category.select($this='problem-list-item').empty())
con-4: If condition is abated, then clinicalStatus must be either inactive, resolved, or remission (abatement.empty() or clinicalStatus.coding.where(system='http://terminology.hl7.org/CodeSystem/condition-clinical' and (code='resolved' or code='remission' or code='inactive')).exists())
con-5: Condition.clinicalStatus SHALL NOT be present if verification Status is entered-in-error (verificationStatus.coding.where(system='http://terminology.hl7.org/CodeSystem/condition-ver-status' and code='entered-in-error').empty() or clinicalStatus.empty())
2. Condition.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. Condition.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.

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

    ERDRI-CDS - The age at which the condition was diagnosed.

    ShortAge at Diagnosis
    Control0..1
    This element is affected by the following invariants: ele-1
    TypeExtension(Age at Diagnosis) (Extension Type: CodeableConcept)
    Is Modifierfalse
    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())
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    8. Condition.extension:age_at_onset
    Slice Nameage_at_onset
    Definition

    ERDRI-CDS - The age at which the condition first appeared.

    ShortAge at Onset
    Control0..1
    This element is affected by the following invariants: ele-1
    TypeExtension(Age at Onset) (Extension Type: CodeableConcept)
    Is Modifierfalse
    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())
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    10. Condition.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())
    12. Condition.clinicalStatus
    Definition

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


    The clinical status of the condition.

    ShortConcept - reference to a terminology or just textactive | recurrence | relapse | inactive | remission | resolved
    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.


    The data type is CodeableConcept because clinicalStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity.

    Control10..1
    This element is affected by the following invariants: ele-1, con-3, con-4, con-5
    BindingThe codes SHALL be taken from Condition Clinical Status Codeshttp://hl7.org/fhir/ValueSet/condition-clinical|4.0.1
    (required to http://terminology.hl7.org/ValueSet/condition-clinical)
    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalsetrue because This element is labeled as a modifier because the status contains codes that mark the condition as no longer active.
    Must Supporttrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    14. Condition.verificationStatus
    Definition

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


    The verification status to support the clinical status of the condition.

    ShortConcept - reference to a terminology or just textunconfirmed | provisional | differential | confirmed | refuted | entered-in-error
    Comments

    This element is labeled as a modifier because the status contains the code refuted and entered-in-error that mark the Condition as not currently valid.


    verificationStatus is not required. For example, when a patient has abdominal pain in the ED, there is not likely going to be a verification status. The data type is CodeableConcept because verificationStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity.

    Control10..1
    This element is affected by the following invariants: ele-1, con-3, con-5
    BindingThe codes SHALL be taken from ConditionVerificationStatushttp://hl7.org/fhir/ValueSet/condition-ver-status|4.0.1
    (required to http://terminology.hl7.org/ValueSet/condition-ver-status)
    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalsetrue because This element is labeled as a modifier because the status contains the code refuted and entered-in-error that mark the Condition as not currently valid.
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    16. Condition.category
    Definition

    A category assigned to the condition. In this profile, a health problem of the patient, therefore a 'problem-list-item'.


    A category assigned to the condition.

    ShortConcept - reference to a terminology or just textproblem-list-item | encounter-diagnosis
    Comments

    In this profile, Condition represents a health problem of the patient. Therefore one of the category value(s) must be problem-list-item.


    The categorization is often highly contextual and may appear poorly differentiated or not very useful in other contexts.

    Control0..*
    This element is affected by the following invariants: ele-1
    BindingUnless not suitable, these codes SHALL be taken from Problem Type - IPShttp://hl7.org/fhir/ValueSet/condition-category
    (extensible to http://hl7.org/fhir/uv/ips/ValueSet/problem-type-uv-ips)
    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalse
    Must Supporttrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    18. Condition.severity
    Definition

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


    A subjective assessment of the severity of the condition as evaluated by the clinician.

    ShortConcept - reference to a terminology or just textSubjective severity of condition
    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.


    Coding of the severity with a terminology is preferred, where possible.

    Control0..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHOULD be taken from Condition/DiagnosisSeverityhttp://hl7.org/fhir/ValueSet/condition-severity
    (preferred to http://hl7.org/fhir/ValueSet/condition-severity)
    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalse
    Must Supporttrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    20. Condition.severity.coding
    Definition

    A reference to a code defined by a terminology system.

    ShortA reference to a code defined by a terminology systemCode defined by a terminology system
    Comments

    Codes may be defined very casually in enumerations or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information.


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

    Control0..1*
    This element is affected by the following invariants: ele-1
    TypeCoding(Coding with translations)
    Is Modifierfalse
    Must Supporttrue
    Requirements

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

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

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

    ShortIdentity of the terminology system
    Comments

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

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

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

    Pattern Valuehttp://snomed.info/sct
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    24. Condition.severity.coding.code
    Definition

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

    ShortSymbol in syntax defined by the system
    Control0..1
    BindingUnless not suitable, these codes SHALL be taken from For codes, see Severity Value Set
    (extensible to https://github.com/BIH-CEI/RareLink/ValueSet/severity-vs)
    Typecode
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

    Need to refer to a particular code in the system.

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

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

    ShortRepresentation defined by the system
    Control0..1
    Typestring
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

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

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    28. Condition.severity.coding.display.extension:translation
    Slice Nametranslation
    Definition

    Language translation from base language of resource to another language.

    ShortLanguage Translation (Localization)
    Control0..*
    TypeExtension(Translation) (Complex Extension)
    Is Modifierfalse
    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())
    30. Condition.severity.text
    Definition

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

    ShortPlain text representation of the concept
    Comments

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

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

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

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

    Identification of the condition, problem or diagnosis or recording of absent/unknown problems.


    Identification of the condition, problem or diagnosis.

    ShortConcept - reference to a terminology or just textIdentification of the condition, problem or diagnosis
    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 Problems - IPShttp://hl7.org/fhir/ValueSet/condition-code
    (preferred to http://hl7.org/fhir/uv/ips/ValueSet/problems-uv-ips)

    Code for a clinical problem (or absent/unknown problem) that is selected from SNOMED CT


    Identification of the condition or diagnosis.

    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()))
    34. Condition.bodySite
    Definition

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


    The anatomical location where this condition manifests itself.

    ShortConcept - reference to a terminology or just textAnatomical location, if relevant
    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.


    Only used if not implicit in code found in Condition.code. If the use case requires attributes from the BodySite resource (e.g. to identify and track separately) then use the standard extension bodySite. May be a summary code, or a reference to a very precise definition of the location, or both.

    Control0..*
    This element is affected by the following invariants: ele-1
    BindingFor example codes, see SNOMEDCTBodyStructureshttp://hl7.org/fhir/ValueSet/body-site
    (example to http://hl7.org/fhir/ValueSet/body-site)
    TypeCodeableConcept(Codeable Concept (IPS))
    Is Modifierfalse
    Must Supporttrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    36. Condition.bodySite.coding
    Definition

    A reference to a code defined by a terminology system.

    ShortA reference to a code defined by a terminology systemCode defined by a terminology system
    Comments

    Codes may be defined very casually in enumerations or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information.


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

    Control0..1*
    This element is affected by the following invariants: ele-1
    TypeCoding(Coding with translations)
    Is Modifierfalse
    Must Supporttrue
    Requirements

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

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

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

    ShortIdentity of the terminology system
    Comments

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

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

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

    Pattern Valuehttp://snomed.info/sct
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    40. Condition.bodySite.coding.code
    Definition

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

    ShortSymbol in syntax defined by the system
    Control0..1
    Typecode
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

    Need to refer to a particular code in the system.

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

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

    ShortRepresentation defined by the system
    Control0..1
    Typestring
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

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

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    44. Condition.bodySite.coding.display.extension:translation
    Slice Nametranslation
    Definition

    Language translation from base language of resource to another language.

    ShortLanguage Translation (Localization)
    Control0..*
    TypeExtension(Translation) (Complex Extension)
    Is Modifierfalse
    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())
    46. Condition.bodySite.text
    Definition

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

    ShortPlain text representation of the concept
    Comments

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

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

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

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

    Indicates the patient or group who the condition record is associated with.

    ShortWho has the condition?
    Control1..1
    TypeReference(RareLink IPS Patient, Patient, Group)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Requirements

    Group is typically used for veterinary or public health use cases.

    Alternate Namespatient
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    50. Condition.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()))
    52. Condition.subject.identifier
    Definition

    An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

    ShortLogical reference, when literal reference is not known
    Comments

    When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.

    When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference

    Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.

    Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any).

    NoteThis is a business identifier, not a resource identifier (see discussion)
    Control0..1
    TypeIdentifier
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    54. Condition.onset[x]
    Definition

    Estimated or actual date or date-time the condition began, in the opinion of the clinician.

    ShortEstimated or actual date, date-time, or age
    Comments

    Age is generally used when the patient reports an age at which the Condition began to occur.

    Control0..1
    TypeChoice of: dateTime, Age, Period, Range, string
    [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
    Must Support TypesdateTime
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    SlicingThis element introduces a set of slices on Condition.onset[x]. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • type @ $this
    • 56. Condition.onset[x]:onsetDateTime
      Slice NameonsetDateTime
      Definition

      Estimated or actual date or date-time the condition began, in the opinion of the clinician.

      ShortEstimated or actual date, date-time, or age
      Comments

      Age is generally used when the patient reports an age at which the Condition began to occur.

      Control0..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
      Must Support TypesdateTime
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))