US Core Implementation Guide
8.0.1 - STU 8

US Core Implementation Guide, published by HL7 International / Cross-Group Projects. This guide is not an authorized publication; it is the continuous build for version 8.0.1 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/US-Core/ and changes regularly. See the Directory of published versions

## Resource Profile: USCoreAllergyIntolerance - Detailed Descriptions

Page standards status: Trial-use | Maturity Level: 3

Definitions for the us-core-allergyintolerance resource profile.

- Key Elements Table
- Differential Elements Table
- Snapshot Elements Table

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

0. AllergyIntolerance
Definition | Risk of harmful or undesirable, physiological response which is unique to an individual and associated with exposure to a substance.
Short | Allergy or Intolerance (generally: Risk of adverse reaction to a substance)
Comments | Substances include, but are not limited to: a therapeutic substance administered correctly at an appropriate dosage for the individual; food; material derived from plants or animals; or venom from insect stings.
Control | 0..*
Is Modifier | false
Must Support | false
Summary | false
Alternate Names | Allergy, Intolerance, Adverse Reaction
Invariants | ait-1: AllergyIntolerance.clinicalStatus SHALL be present if verificationStatus is not entered-in-error. (`verificationStatus.coding.where(system = 'http://terminology.hl7.org/CodeSystem/allergyintolerance-verification' and code = 'entered-in-error').exists() or clinicalStatus.exists()`) ait-2: AllergyIntolerance.clinicalStatus SHALL NOT be present if verification Status is entered-in-error (`verificationStatus.coding.where(system = 'http://terminology.hl7.org/CodeSystem/allergyintolerance-verification' 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()) ait-1: AllergyIntolerance.clinicalStatus SHALL be present if verificationStatus is not entered-in-error. (verificationStatus.coding.where(system = 'http://terminology.hl7.org/CodeSystem/allergyintolerance-verification' and code = 'entered-in-error').exists() or clinicalStatus.exists()) ait-2: AllergyIntolerance.clinicalStatus SHALL NOT be present if verification Status is entered-in-error (verificationStatus.coding.where(system = 'http://terminology.hl7.org/CodeSystem/allergyintolerance-verification' and code = 'entered-in-error').empty() or clinicalStatus.empty())
2. AllergyIntolerance.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.
Short | A 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.
Control | 0..1
Type | uri
Is Modifier | true 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 Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. AllergyIntolerance.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).
Short | Extensions 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.
Control | 0..*
Type | Extension
Is Modifier | true because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Summary | false
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 Names | extensions, user content
Invariants | ele-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())
6. AllergyIntolerance.clinicalStatus
Definition | The clinical status of the allergy or intolerance.
Short | active | inactive | resolved
Comments | Refer to discussion if clincalStatus is missing data. 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.
Control | 0..1 This element is affected by the following invariants: ait-1, ait-2
Binding | The codes SHALL be taken from AllergyIntoleranceClinicalStatusCodes http://hl7.org/fhir/ValueSet/allergyintolerance-clinical|4.0.1 (required to `http://hl7.org/fhir/ValueSet/allergyintolerance-clinical` )
Type | CodeableConcept
Is Modifier | true because This element is labeled as a modifier because the status contains the codes inactive and resolved that mark the AllergyIntolerance as no longer active.
Must Support | true
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
8. AllergyIntolerance.verificationStatus
Definition | Assertion about certainty associated with the propensity, or potential risk, of a reaction to the identified substance (including pharmaceutical product).
Short | unconfirmed | confirmed | refuted | entered-in-error
Comments | 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.
Control | 0..1 This element is affected by the following invariants: ait-1, ait-2
Binding | The codes SHALL be taken from AllergyIntoleranceVerificationStatusCodes http://hl7.org/fhir/ValueSet/allergyintolerance-verification|4.0.1 (required to `http://hl7.org/fhir/ValueSet/allergyintolerance-verification` )
Type | CodeableConcept
Is Modifier | true because This element is labeled as a modifier because the status contains the codes refuted and entered-in-error that mark the AllergyIntolerance as not currently valid.
Must Support | true
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
10. AllergyIntolerance.code
Definition | Code for an allergy or intolerance statement (either a positive or a negated/excluded statement). This may be a code for a substance or pharmaceutical product that is considered to be responsible for the adverse reaction risk (e.g., "Latex"), an allergy or intolerance condition (e.g., "Latex allergy"), or a negated/excluded code for a specific substance or class (e.g., "No latex allergy") or a general or categorical negated statement (e.g., "No known allergy", "No known drug allergies"). Note: the substance for a specific reaction may be different from the substance identified as the cause of the risk, but it must be consistent with it. For instance, it may be a more specific substance (e.g. a brand medication) or a composite product that includes the identified substance. It must be clinically safe to only process the 'code' and ignore the 'reaction.substance'. If a receiving system is unable to confirm that AllergyIntolerance.reaction.substance falls within the semantic scope of AllergyIntolerance.code, then the receiving system should ignore AllergyIntolerance.reaction.substance.
Short | Code that identifies the allergy or intolerance
Comments | It is strongly recommended that this element be populated using a terminology, where possible. For example, some terminologies used include RxNorm, SNOMED CT, DM+D, NDFRT, ICD-9, IDC-10, UNII, and ATC. Plain text should only be used if there is no appropriate terminology available. Additional details can be specified in the text. When a substance or product code is specified for the 'code' element, the "default" semantic context is that this is a positive statement of an allergy or intolerance (depending on the value of the 'type' element, if present) condition to the specified substance/product. In the corresponding SNOMED CT allergy model, the specified substance/product is the target (destination) of the "Causative agent" relationship. The 'substanceExposureRisk' extension is available as a structured and more flexible alternative to the 'code' element for making positive or negative allergy or intolerance statements. This extension provides the capability to make "no known allergy" (or "no risk of adverse reaction") statements regarding any coded substance/product (including cases when a pre-coordinated "no allergy to x" concept for that substance/product does not exist). If the 'substanceExposureRisk' extension is present, the AllergyIntolerance.code element SHALL be omitted.
Control | 10..1
Binding | Unless not suitable, these codes SHALL be taken from For example codes, see Common substances for allergy and intolerance documentation including refutations http://hl7.org/fhir/ValueSet/allergyintolerance-code|4.0.1 (extensible to `http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1186.8` )
Type | CodeableConcept
Is Modifier | false
Must Support | true
Summary | true
Alternate Names | Code
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. AllergyIntolerance.patient
Definition | The patient who has the allergy or intolerance.
Short | Who the sensitivity is for
Control | 1..1
Type | Reference(US Core Patient Profile, Patient)
Is Modifier | false
Must Support | true
Summary | true
Alternate Names | Patient
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. AllergyIntolerance.recorder
Definition | Individual who recorded the record and takes responsibility for its content.
Short | Changed:𝗔𝗗𝗗𝗜𝗧𝗜𝗢𝗡𝗔𝗟 𝗨𝗦𝗖𝗗𝗜: Who recorded the sensitivity Who recorded the sensitivity
Control | 0..1
Type | Reference(US Core Practitioner Profile, US Core Patient Profile, PractitionerRole, US Core RelatedPerson Profile, Practitioner, PractitionerRole, Patient, RelatedPerson)
Is Modifier | false
Summary | false
Alternate Names | Author
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
16. AllergyIntolerance.reaction
Definition | Details about each adverse reaction event linked to exposure to the identified substance.
Short | Adverse Reaction Events linked to exposure to substance
Control | 0..*
Type | BackboneElement
Is Modifier | false
Must Support | true
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
18. AllergyIntolerance.reaction.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).
Short | Extensions 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.
Control | 0..*
Type | Extension
Is Modifier | true because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
Summary | true
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 Names | extensions, user content, modifiers
Invariants | ele-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())
20. AllergyIntolerance.reaction.manifestation
Definition | Clinical symptoms and/or signs that are observed or associated with the adverse reaction event.
Short | Clinical symptoms/signs associated with the Event
Comments | Manifestation can be expressed as a single word, phrase or brief description. For example: nausea, rash or no reaction. It is preferable that manifestation should be coded with a terminology, where possible. The values entered here may be used to display on an application screen as part of a list of adverse reactions, as recommended in the UK NHS CUI guidelines. Terminologies commonly used include, but are not limited to, SNOMED CT or ICD10.
Control | 1..*
Binding | Unless not suitable, these codes SHALL be taken from For example codes, see SNOMEDCTClinicalFindings http://hl7.org/fhir/ValueSet/clinical-findings|4.0.1 (extensible to `http://hl7.org/fhir/ValueSet/clinical-findings` )
Type | CodeableConcept
Is Modifier | false
Must Support | true
Summary | false
Alternate Names | Symptoms, Signs
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

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

0. AllergyIntolerance
Must Support | false
2. AllergyIntolerance.clinicalStatus
Binding | The codes SHALL be taken from AllergyIntoleranceClinicalStatusCodes (required to `http://hl7.org/fhir/ValueSet/allergyintolerance-clinical` )
Must Support | true
4. AllergyIntolerance.verificationStatus
Binding | The codes SHALL be taken from AllergyIntoleranceVerificationStatusCodes (required to `http://hl7.org/fhir/ValueSet/allergyintolerance-verification` )
Must Support | true
6. AllergyIntolerance.code
Control | 1..?
Binding | Unless not suitable, these codes SHALL be taken from Common substances for allergy and intolerance documentation including refutations (extensible to `http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1186.8` )
Must Support | true
8. AllergyIntolerance.patient
Type | Reference(US Core Patient Profile)
Must Support | true
Added: 10. AllergyIntolerance.recorder
Short | 𝗔𝗗𝗗𝗜𝗧𝗜𝗢𝗡𝗔𝗟 𝗨𝗦𝗖𝗗𝗜: Who recorded the sensitivity
Type | Reference(US Core Practitioner Profile, US Core Patient Profile, PractitionerRole, US Core RelatedPerson Profile)
12. AllergyIntolerance.reaction
Must Support | true
14. AllergyIntolerance.reaction.manifestation
Binding | Unless not suitable, these codes SHALL be taken from SNOMEDCTClinicalFindings (extensible to `http://hl7.org/fhir/ValueSet/clinical-findings` )
Must Support | true

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

0. AllergyIntolerance
Definition | Risk of harmful or undesirable, physiological response which is unique to an individual and associated with exposure to a substance.
Short | Allergy or Intolerance (generally: Risk of adverse reaction to a substance)
Comments | Substances include, but are not limited to: a therapeutic substance administered correctly at an appropriate dosage for the individual; food; material derived from plants or animals; or venom from insect stings.
Control | 0..*
Is Modifier | false
Must Support | false
Summary | false
Alternate Names | Allergy, Intolerance, Adverse Reaction
Invariants | ait-1: AllergyIntolerance.clinicalStatus SHALL be present if verificationStatus is not entered-in-error. (`verificationStatus.coding.where(system = 'http://terminology.hl7.org/CodeSystem/allergyintolerance-verification' and code = 'entered-in-error').exists() or clinicalStatus.exists()`) ait-2: AllergyIntolerance.clinicalStatus SHALL NOT be present if verification Status is entered-in-error (`verificationStatus.coding.where(system = 'http://terminology.hl7.org/CodeSystem/allergyintolerance-verification' 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()`)
2. AllergyIntolerance.id
Definition | The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.
Short | Logical 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.
Control | 0..1
Type | id
Is Modifier | false
Summary | true
4. AllergyIntolerance.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.
Short | Metadata about the resource
Control | 0..1
Type | Meta
Is Modifier | false
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
6. AllergyIntolerance.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.
Short | A 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.
Control | 0..1
Type | uri
Is Modifier | true 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 Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
8. AllergyIntolerance.language
Definition | The base language in which the resource is written.
Short | Language 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).
Control | 0..1
Binding | The codes SHOULD be taken from CommonLanguages (preferred to `http://hl7.org/fhir/ValueSet/languages|4.0.1` ) A human language.
Additional Bindings | Purpose
AllLanguages | Max Binding
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
10. AllergyIntolerance.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.
Short | Text 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.
Control | 0..1
Type | Narrative
Is Modifier | false
Summary | false
Alternate Names | narrative, html, xhtml, display
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
12. AllergyIntolerance.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.
Short | Contained, 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.
Control | 0..*
Type | Resource
Is Modifier | false
Summary | false
Alternate Names | inline resources, anonymous resources, contained resources
14. AllergyIntolerance.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.
Short | Additional 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.
Control | 0..*
Type | Extension
Is Modifier | false
Summary | false
Alternate Names | extensions, user content
Invariants | ele-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()`)
16. AllergyIntolerance.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).
Short | Extensions 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.
Control | 0..*
Type | Extension
Is Modifier | true because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Summary | false
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 Names | extensions, user content
Invariants | ele-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. AllergyIntolerance.identifier
Definition | Business identifiers assigned to this AllergyIntolerance by the performer or other systems which remain constant as the resource is updated and propagates from server to server.
Short | External ids for this item
Comments | This is a business identifier, not a resource identifier (see discussion). It is best practice for the identifier to only appear on a single resource instance, however business practices may occasionally dictate that multiple resource instances with the same identifier can exist - possibly even with different resource types. For example, multiple Patient and a Person resource instance might share the same social insurance number.
Note | This is a business identifier, not a resource identifier (see discussion)
Control | 0..*
Type | Identifier
Is Modifier | false
Summary | true
Requirements | Allows identification of the AllergyIntolerance as it is known by various participating systems and in a way that remains consistent across servers.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
20. AllergyIntolerance.clinicalStatus
Definition | The clinical status of the allergy or intolerance.
Short | active | inactive | resolved
Comments | Refer to discussion if clincalStatus is missing data. 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.
Control | 0..1 This element is affected by the following invariants: ait-1, ait-2
Binding | The codes SHALL be taken from AllergyIntoleranceClinicalStatusCodes (required to `http://hl7.org/fhir/ValueSet/allergyintolerance-clinical` )
Type | CodeableConcept
Is Modifier | true because This element is labeled as a modifier because the status contains the codes inactive and resolved that mark the AllergyIntolerance as no longer active.
Must Support | true
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
22. AllergyIntolerance.verificationStatus
Definition | Assertion about certainty associated with the propensity, or potential risk, of a reaction to the identified substance (including pharmaceutical product).
Short | unconfirmed | confirmed | refuted | entered-in-error
Comments | 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.
Control | 0..1 This element is affected by the following invariants: ait-1, ait-2
Binding | The codes SHALL be taken from AllergyIntoleranceVerificationStatusCodes (required to `http://hl7.org/fhir/ValueSet/allergyintolerance-verification` )
Type | CodeableConcept
Is Modifier | true because This element is labeled as a modifier because the status contains the codes refuted and entered-in-error that mark the AllergyIntolerance as not currently valid.
Must Support | true
Summary | true
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
24. AllergyIntolerance.type
Definition | Identification of the underlying physiological mechanism for the reaction risk.
Short | allergy | intolerance - Underlying mechanism (if known)
Comments | Allergic (typically immune-mediated) reactions have been traditionally regarded as an indicator for potential escalation to significant future risk. Contemporary knowledge suggests that some reactions previously thought to be immune-mediated are, in fact, non-immune, but in some cases can still pose a life threatening risk. It is acknowledged that many clinicians might not be in a position to distinguish the mechanism of a particular reaction. Often the term "allergy" is used rather generically and may overlap with the use of "intolerance" - in practice the boundaries between these two concepts might not be well-defined or understood. This data element is included nevertheless, because many legacy systems have captured this attribute. Immunologic testing may provide supporting evidence for the basis of the reaction and the causative substance, but no tests are 100% sensitive or specific for sensitivity to a particular substance. If, as is commonly the case, it is unclear whether the reaction is due to an allergy or an intolerance, then the type element should be omitted from the resource.
Control | 0..1
Binding | The codes SHALL be taken from AllergyIntoleranceType (required to `http://hl7.org/fhir/ValueSet/allergy-intolerance-type|4.0.1` ) Identification of the underlying physiological mechanism for a Reaction Risk.
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Alternate Names | Category, Class
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
26. AllergyIntolerance.category
Definition | Category of the identified substance.
Short | food | medication | environment | biologic
Comments | This data element has been included because it is currently being captured in some clinical systems. This data can be derived from the substance where coding systems are used, and is effectively redundant in that situation. When searching on category, consider the implications of AllergyIntolerance resources without a category. For example, when searching on category = medication, medication allergies that don't have a category valued will not be returned. Refer to search for more information on how to search category with a :missing modifier to get allergies that don't have a category. Additionally, category should be used with caution because category can be subjective based on the sender.
Control | 0..*
Binding | The codes SHALL be taken from AllergyIntoleranceCategory (required to `http://hl7.org/fhir/ValueSet/allergy-intolerance-category|4.0.1` ) Category of an identified substance associated with allergies or intolerances.
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Alternate Names | Category, Type, Reaction Type, Class
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
28. AllergyIntolerance.criticality
Definition | Estimate of the potential clinical harm, or seriousness, of the reaction to the identified substance.
Short | low | high | unable-to-assess
Comments | The default criticality value for any propensity to an adverse reaction should be 'Low Risk', indicating at the very least a relative contraindication to deliberate or voluntary exposure to the substance. 'High Risk' is flagged if the clinician has identified a propensity for a more serious or potentially life-threatening reaction, such as anaphylaxis, and implies an absolute contraindication to deliberate or voluntary exposure to the substance. If this element is missing, the criticality is unknown (though it may be known elsewhere). Systems that capture a severity at the condition level are actually representing the concept of criticality whereas the severity documented at the reaction level is representing the true reaction severity. Existing systems that are capturing both condition criticality and reaction severity may use the term "severity" to represent both. Criticality is the worst it could be in the future (i.e. situation-agnostic) whereas severity is situation-dependent.
Control | 0..1
Binding | The codes SHALL be taken from AllergyIntoleranceCriticality (required to `http://hl7.org/fhir/ValueSet/allergy-intolerance-criticality|4.0.1` ) Estimate of the potential clinical harm, or seriousness, of a reaction to an identified substance.
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Alternate Names | Severity, Seriousness, Contra-indication, Risk
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
30. AllergyIntolerance.code
Definition | Code for an allergy or intolerance statement (either a positive or a negated/excluded statement). This may be a code for a substance or pharmaceutical product that is considered to be responsible for the adverse reaction risk (e.g., "Latex"), an allergy or intolerance condition (e.g., "Latex allergy"), or a negated/excluded code for a specific substance or class (e.g., "No latex allergy") or a general or categorical negated statement (e.g., "No known allergy", "No known drug allergies"). Note: the substance for a specific reaction may be different from the substance identified as the cause of the risk, but it must be consistent with it. For instance, it may be a more specific substance (e.g. a brand medication) or a composite product that includes the identified substance. It must be clinically safe to only process the 'code' and ignore the 'reaction.substance'. If a receiving system is unable to confirm that AllergyIntolerance.reaction.substance falls within the semantic scope of AllergyIntolerance.code, then the receiving system should ignore AllergyIntolerance.reaction.substance.
Short | Code that identifies the allergy or intolerance
Comments | It is strongly recommended that this element be populated using a terminology, where possible. For example, some terminologies used include RxNorm, SNOMED CT, DM+D, NDFRT, ICD-9, IDC-10, UNII, and ATC. Plain text should only be used if there is no appropriate terminology available. Additional details can be specified in the text. When a substance or product code is specified for the 'code' element, the "default" semantic context is that this is a positive statement of an allergy or intolerance (depending on the value of the 'type' element, if present) condition to the specified substance/product. In the corresponding SNOMED CT allergy model, the specified substance/product is the target (destination) of the "Causative agent" relationship. The 'substanceExposureRisk' extension is available as a structured and more flexible alternative to the 'code' element for making positive or negative allergy or intolerance statements. This extension provides the capability to make "no known allergy" (or "no risk of adverse reaction") statements regarding any coded substance/product (including cases when a pre-coordinated "no allergy to x" concept for that substance/product does not exist). If the 'substanceExposureRisk' extension is present, the AllergyIntolerance.code element SHALL be omitted.
Control | 1..1
Binding | Unless not suitable, these codes SHALL be taken from Common substances for allergy and intolerance documentation including refutations (extensible to `http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1186.8` )
Type | CodeableConcept
Is Modifier | false
Must Support | true
Summary | true
Alternate Names | Code
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
32. AllergyIntolerance.patient
Definition | The patient who has the allergy or intolerance.
Short | Who the sensitivity is for
Control | 1..1
Type | Reference(US Core Patient Profile)
Is Modifier | false
Must Support | true
Summary | true
Alternate Names | Patient
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
34. AllergyIntolerance.encounter
Definition | The encounter when the allergy or intolerance was asserted.
Short | Encounter when the allergy or intolerance was asserted
Control | 0..1
Type | Reference(Encounter)
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
36. AllergyIntolerance.onset[x]
Definition | Estimated or actual date, date-time, or age when allergy or intolerance was identified.
Short | When allergy or intolerance was identified
Control | 0..1
Type | Choice of: dateTime, Age, Period, Range, string
[x] Note | SeeChoice of Data Typesfor further information about how to use [x]
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
38. AllergyIntolerance.recordedDate
Definition | The recordedDate represents when this particular AllergyIntolerance record was created in the system, which is often a system-generated date.
Short | Date first version of the resource instance was recorded
Control | 0..1
Type | dateTime
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
40. AllergyIntolerance.recorder
Definition | Individual who recorded the record and takes responsibility for its content.
Short | Changed:𝗔𝗗𝗗𝗜𝗧𝗜𝗢𝗡𝗔𝗟 𝗨𝗦𝗖𝗗𝗜: Who recorded the sensitivity
Control | 0..1
Type | Reference(US Core Practitioner Profile, US Core Patient Profile, PractitionerRole, US Core RelatedPerson Profile)
Is Modifier | false
Summary | false
Alternate Names | Author
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
42. AllergyIntolerance.asserter
Definition | The source of the information about the allergy that is recorded.
Short | Source of the information about the allergy
Comments | The recorder takes responsibility for the content, but can reference the source from where they got it.
Control | 0..1
Type | Reference(Patient, RelatedPerson, Practitioner, PractitionerRole)
Is Modifier | false
Summary | true
Alternate Names | Source, Informant
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
44. AllergyIntolerance.lastOccurrence
Definition | Represents the date and/or time of the last known occurrence of a reaction event.
Short | Date(/time) of last known occurrence of a reaction
Comments | This date may be replicated by one of the Onset of Reaction dates. Where a textual representation of the date of last occurrence is required e.g. 'In Childhood, '10 years ago' the Comment element should be used.
Control | 0..1
Type | dateTime
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
46. AllergyIntolerance.note
Definition | Additional narrative about the propensity for the Adverse Reaction, not captured in other fields.
Short | Additional text not captured in other fields
Comments | For example: including reason for flagging a seriousness of 'High Risk'; and instructions related to future exposure or administration of the substance, such as administration within an Intensive Care Unit or under corticosteroid cover. The notes should be related to an allergy or intolerance as a condition in general and not related to any particular episode of it. For episode notes and descriptions, use AllergyIntolerance.event.description and AllergyIntolerance.event.notes.
Control | 0..*
Type | Annotation
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
48. AllergyIntolerance.reaction
Definition | Details about each adverse reaction event linked to exposure to the identified substance.
Short | Adverse Reaction Events linked to exposure to substance
Control | 0..*
Type | BackboneElement
Is Modifier | false
Must Support | true
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
50. AllergyIntolerance.reaction.id
Definition | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short | Unique id for inter-element referencing
Control | 0..1
Type | string
Is Modifier | false
XML Format | In the XML format, this property is represented as an attribute.
Summary | false
52. AllergyIntolerance.reaction.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.
Short | Additional 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.
Control | 0..*
Type | Extension
Is Modifier | false
Summary | false
Alternate Names | extensions, user content
Invariants | ele-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()`)
54. AllergyIntolerance.reaction.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).
Short | Extensions 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.
Control | 0..*
Type | Extension
Is Modifier | true because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
Summary | true
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 Names | extensions, user content, modifiers
Invariants | ele-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()`)
56. AllergyIntolerance.reaction.substance
Definition | Identification of the specific substance (or pharmaceutical product) considered to be responsible for the Adverse Reaction event. Note: the substance for a specific reaction may be different from the substance identified as the cause of the risk, but it must be consistent with it. For instance, it may be a more specific substance (e.g. a brand medication) or a composite product that includes the identified substance. It must be clinically safe to only process the 'code' and ignore the 'reaction.substance'. If a receiving system is unable to confirm that AllergyIntolerance.reaction.substance falls within the semantic scope of AllergyIntolerance.code, then the receiving system should ignore AllergyIntolerance.reaction.substance.
Short | Specific substance or pharmaceutical product considered to be responsible for event
Comments | Coding of the specific substance (or pharmaceutical product) with a terminology capable of triggering decision support should be used wherever possible. The 'code' element allows for the use of a specific substance or pharmaceutical product, or a group or class of substances. In the case of an allergy or intolerance to a class of substances, (for example, "penicillins"), the 'reaction.substance' element could be used to code the specific substance that was identified as having caused the reaction (for example, "amoxycillin"). Duplication of the value in the 'code' and 'reaction.substance' elements is acceptable when a specific substance has been recorded in 'code'.
Control | 0..1
Binding | For example codes, see SubstanceCode (example to `http://hl7.org/fhir/ValueSet/substance-code|4.0.1` ) Codes defining the type of the substance (including pharmaceutical products).
Type | CodeableConcept
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
58. AllergyIntolerance.reaction.manifestation
Definition | Clinical symptoms and/or signs that are observed or associated with the adverse reaction event.
Short | Clinical symptoms/signs associated with the Event
Comments | Manifestation can be expressed as a single word, phrase or brief description. For example: nausea, rash or no reaction. It is preferable that manifestation should be coded with a terminology, where possible. The values entered here may be used to display on an application screen as part of a list of adverse reactions, as recommended in the UK NHS CUI guidelines. Terminologies commonly used include, but are not limited to, SNOMED CT or ICD10.
Control | 1..*
Binding | Unless not suitable, these codes SHALL be taken from SNOMEDCTClinicalFindings (extensible to `http://hl7.org/fhir/ValueSet/clinical-findings` )
Type | CodeableConcept
Is Modifier | false
Must Support | true
Summary | false
Alternate Names | Symptoms, Signs
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
60. AllergyIntolerance.reaction.description
Definition | Text description about the reaction as a whole, including details of the manifestation if required.
Short | Description of the event as a whole
Comments | Use the description to provide any details of a particular event of the occurred reaction such as circumstances, reaction specifics, what happened before/after. Information, related to the event, but not describing a particular care should be captured in the comment field. For example: at the age of four, the patient was given penicillin for strep throat and subsequently developed severe hives.
Control | 0..1
Type | string
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Alternate Names | Narrative, Text
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
62. AllergyIntolerance.reaction.onset
Definition | Record of the date and/or time of the onset of the Reaction.
Short | Date(/time) when manifestations showed
Control | 0..1
Type | dateTime
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
64. AllergyIntolerance.reaction.severity
Definition | Clinical assessment of the severity of the reaction event as a whole, potentially considering multiple different manifestations.
Short | mild | moderate | severe (of event as a whole)
Comments | It is acknowledged that this assessment is very subjective. There may be some specific practice domains where objective scales have been applied. Objective scales can be included in this model as extensions.
Control | 0..1
Binding | The codes SHALL be taken from AllergyIntoleranceSeverity (required to `http://hl7.org/fhir/ValueSet/reaction-event-severity|4.0.1` ) Clinical assessment of the severity of a reaction event as a whole, potentially considering multiple different manifestations.
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
66. AllergyIntolerance.reaction.exposureRoute
Definition | Identification of the route by which the subject was exposed to the substance.
Short | How the subject was exposed to the substance
Comments | Coding of the route of exposure with a terminology should be used wherever possible.
Control | 0..1
Binding | For example codes, see SNOMEDCTRouteCodes (example to `http://hl7.org/fhir/ValueSet/route-codes|4.0.1` ) A coded concept describing the route or physiological path of administration of a therapeutic agent into or onto the body of a subject.
Type | CodeableConcept
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
68. AllergyIntolerance.reaction.note
Definition | Additional text about the adverse reaction event not captured in other fields.
Short | Text about event not captured in other fields
Comments | Use this field to record information indirectly related to a particular event and not captured in the description. For example: Clinical records are no longer available, recorded based on information provided to the patient by her mother and her mother is deceased.
Control | 0..*
Type | Annotation
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)