US Core Implementation Guide (Release 1.0.1)

This page is part of the US Core (v1.0.1: STU1) based on FHIR R3. The current version which supercedes this version is 5.0.1. For a full list of available versions, see the Directory of published versions

D.4.1.4 StructureDefinition: - Detailed Descriptions

Definitions for the StructureDefinition-us-core-allergyintolerance Profile.

AllergyIntolerance
Definition

The US Core Allergies Profile is based upon the core FHIR AllergyIntolerance Resource and created to meet the 2015 Edition Common Clinical Data Set 'Medical allergies' requirements.

Control0..*
Alternate NamesAllergy, Intolerance, Adverse Reaction
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.

InvariantsDefined on this element
ait-1: AllergyIntolerance.clinicalStatus SHALL be present if verificationStatus is not entered-in-error. (: verificationStatus='entered-in-error' or clinicalStatus.exists())
ait-2: AllergyIntolerance.clinicalStatus SHALL NOT be present if verification Status is entered-in-error (: verificationStatus!='entered-in-error' or clinicalStatus.empty())
dom-1: If the resource is contained in another resource, it SHALL NOT contain any narrative (: contained.text.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 (: contained.where(('#'+id in %resource.descendants().reference).not()).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())
AllergyIntolerance.id
Definition

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

Control0..1
Typeid
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.

AllergyIntolerance.meta
Definition

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

Control0..1
TypeMeta
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.

Control0..1
Typeuri
Is Modifiertrue
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.

This element is labelled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation.

AllergyIntolerance.language
Definition

The base language in which the resource is written.

Control0..1
BindingA human language.
The codes SHALL be taken from Common Languages; other codes may be used where these codes are not suitable
Typecode
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).

AllergyIntolerance.text
Definition

A human-readable narrative that contains a summary of the resource, and may 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.

Control0..1 This element is affected by the following invariants: dom-1
TypeNarrative
Alternate Namesnarrative, html, xhtml, display
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 in formation is added later.

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.

Control0..*
TypeResource
Alternate Namesinline resources, anonymous resources, contained 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.

AllergyIntolerance.extension
Definition

May be used to represent additional information that is not part of the basic definition of the resource. In order 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
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.

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. Usually modifier elements provide negation or qualification. In order 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.

Control0..*
TypeExtension
Is Modifiertrue
Alternate Namesextensions, user content
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.

AllergyIntolerance.identifier
Definition

This records identifiers associated with this allergy/intolerance concern that are defined by business processes and/or used to refer to it when a direct URL reference to the resource itself is not appropriate (e.g. in CDA documents, or in written / printed documentation).

NoteThis is a business identifer, not a resource identifier (see discussion)
Control0..*
TypeIdentifier
AllergyIntolerance.clinicalStatus
Definition

The clinical status of the allergy or intolerance.

Control0..1 This element is affected by the following invariants: ait-1, ait-2
BindingThe codes SHALL be taken from AllergyIntoleranceClinicalStatus
Typecode
Is Modifiertrue
Must Supporttrue
Comments

This element is labeled as a modifier because the status contains the codes inactive and resolved that mark the AllergyIntolerance as not currently valid.

AllergyIntolerance.verificationStatus
Definition

Assertion about certainty associated with the propensity, or potential risk, of a reaction to the identified substance (including pharmaceutical product).

Control1..1 This element is affected by the following invariants: ait-1, ait-2
BindingThe codes SHALL be taken from AllergyIntoleranceVerificationStatus
Typecode
Is Modifiertrue
Must Supporttrue
Comments

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.

AllergyIntolerance.type
Definition

Identification of the underlying physiological mechanism for the reaction risk.

Control0..1
BindingIdentification of the underlying physiological mechanism for a Reaction Risk.
The codes SHALL be taken from AllergyIntoleranceType
Typecode
Alternate NamesCategory, Class
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 may 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 may 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.

AllergyIntolerance.category
Definition

Category of the identified substance.

Control0..*
BindingCategory of an identified substance.
The codes SHALL be taken from AllergyIntoleranceCategory
Typecode
Alternate NamesCategory, Type, Reaction Type, Class
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.

AllergyIntolerance.criticality
Definition

Estimate of the potential clinical harm, or seriousness, of the reaction to the identified substance.

Control0..1
BindingEstimate of the potential clinical harm, or seriousness, of a reaction to an identified substance.
The codes SHALL be taken from AllergyIntoleranceCriticality
Typecode
Alternate NamesSeverity, Seriousness, Contra-indication, Risk
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.

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").

Control1..1
BindingThe codes SHALL be taken from US Core Substance-Reactant for Intolerance and Negation Codes; other codes may be used where these codes are not suitable
TypeCodeableConcept
Must Supporttrue
Alternate NamesCode
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, UNI, ATC and CPT. 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.

AllergyIntolerance.patient
Definition

The patient who has the allergy or intolerance.

Control1..1
TypeReference(US Core Patient Profile)
Must Supporttrue
Alternate NamesPatient
AllergyIntolerance.onset[x]
Definition

Estimated or actual date, date-time, or age when allergy or intolerance was identified.

Control0..1
TypeChoice of: dateTime, Age, Period, Range, string
[x] NoteSee Choice of Data Types for further information about how to use [x]
AllergyIntolerance.assertedDate
Definition

The date on which the existance of the AllergyIntolerance was first asserted or acknowledged.

Control0..1
TypedateTime
AllergyIntolerance.recorder
Definition

Individual who recorded the record and takes responsibility for its content.

Control0..1
TypeChoice of: Reference(Practitioner), Reference(Patient)
Alternate NamesAuthor
AllergyIntolerance.asserter
Definition

The source of the information about the allergy that is recorded.

Control0..1
TypeChoice of: Reference(Patient), Reference(RelatedPerson), Reference(Practitioner)
Alternate NamesSource, Informant
Comments

The recorder takes repsonsibility for the content, but can reference the source from where they got it.

AllergyIntolerance.lastOccurrence
Definition

Represents the date and/or time of the last known occurrence of a reaction event.

Control0..1
TypedateTime
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.

AllergyIntolerance.note
Definition

Additional narrative about the propensity for the Adverse Reaction, not captured in other fields.

Control0..*
TypeAnnotation
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.

AllergyIntolerance.reaction
Definition

Details about each adverse reaction event linked to exposure to the identified substance.

Control0..*
TypeBackboneElement
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() | (children().count() > id.count()))
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.

Control0..1
Typestring
AllergyIntolerance.reaction.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. In order 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.

Control0..*
TypeExtension
Alternate Namesextensions, user content
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.

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 that contains it. Usually modifier elements provide negation or qualification. In order 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.

Control0..*
TypeExtension
Is Modifiertrue
Alternate Namesextensions, user content, modifiers
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.

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'.

Control0..1
BindingCodes defining the type of the substance (including pharmaceutical products).
For example codes, see Substance Code
TypeCodeableConcept
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 identifed 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'.

AllergyIntolerance.reaction.manifestation
Definition

Clinical symptoms and/or signs that are observed or associated with the adverse reaction event.

Control1..*
BindingClinical symptoms and/or signs that are observed or associated with an Adverse Reaction Event.
For example codes, see SNOMED CT Clinical Findings
TypeCodeableConcept
Alternate NamesSymptoms, Signs
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.

AllergyIntolerance.reaction.description
Definition

Text description about the reaction as a whole, including details of the manifestation if required.

Control0..1
Typestring
Alternate NamesNarrative, Text
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.

AllergyIntolerance.reaction.onset
Definition

Record of the date and/or time of the onset of the Reaction.

Control0..1
TypedateTime
AllergyIntolerance.reaction.severity
Definition

Clinical assessment of the severity of the reaction event as a whole, potentially considering multiple different manifestations.

Control0..1
BindingClinical assessment of the severity of a reaction event as a whole, potentially considering multiple different manifestations.
The codes SHALL be taken from AllergyIntoleranceSeverity
Typecode
Comments

It is acknowledged that this assessment is very subjective. There may be some some specific practice domains where objective scales have been applied. Objective scales can be included in this model as extensions.

AllergyIntolerance.reaction.exposureRoute
Definition

Identification of the route by which the subject was exposed to the substance.

Control0..1
BindingA coded concept describing the route or physiological path of administration of a therapeutic agent into or onto the body of a subject.
For example codes, see SNOMED CT Route Codes
TypeCodeableConcept
Comments

Coding of the route of exposure with a terminology should be used wherever possible.

AllergyIntolerance.reaction.note
Definition

Additional text about the adverse reaction event not captured in other fields.

Control0..*
TypeAnnotation
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.