HRSA 2023 Uniform Data System (UDS) Patient Level Submission (PLS) (UDS+) FHIR IG
1.1.0 - STU1 Release 1.1 - Standard for Trial-Use International flag

This page is part of the HRSA Uniform Data System (UDS) Patient Level Submission (PLS) (UDS+ or uds-plus) FHIR IG (v1.1.0: STU1) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version. For a full list of available versions, see the Directory of published versions

Resource Profile: UDSPlusAllergyIntolerance - Detailed Descriptions

Page standards status: Trial-use Maturity Level: 2

Definitions for the uds-plus-allergyintolerance resource profile.

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

0. AllergyIntolerance
Definition

The UDS+ profile is based on the AllergyIntolerance resource and establishes the core elements, extensions, vocabularies and value sets for representing AllergyIntolerance for UDS+ program.

ShortDe-Identified UDS Plus AllergyIntolerance
2. AllergyIntolerance.id
Definition

De-dentified AllergyIntolerance resource identifier.

ShortThe de-identified AllergyIntolerance identifier created by the health center to send data to UDS+ Data Receiver
Must Supporttrue
4. AllergyIntolerance.text
ShortCannot include any text in the resource as part of the de-identified data.
Control0..0
Must Supportfalse
6. AllergyIntolerance.contained
ShortCannot include any contained resources in the resource as part of the de-identified data.
Control0..0
Must Supportfalse
8. AllergyIntolerance.clinicalStatus
Control0..1
Must Supporttrue
10. AllergyIntolerance.verificationStatus
Control0..1
Must Supporttrue
12. AllergyIntolerance.type
Control0..1
Must Supporttrue
14. AllergyIntolerance.category
Control0..*
Must Supporttrue
16. AllergyIntolerance.criticality
Control0..1
Must Supporttrue
18. AllergyIntolerance.code
Control1..1
BindingUnless 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)

The set of codes indicating the allergy or intolerance

Must Supporttrue
20. AllergyIntolerance.patient
Control1..1
TypeReference(De-Identified UDS Plus Patient)
Must Supporttrue
22. AllergyIntolerance.patient.display
Control0..0
Must Supportfalse
24. AllergyIntolerance.encounter
26. AllergyIntolerance.encounter.display
Control0..0
Must Supportfalse
28. AllergyIntolerance.onset[x]
Control0..1
TypeChoice of: dateTime, Age, string, Period, Range
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Must Support TypesNo must-support rules about the choice of types/profiles
Invariantsuds-plus-all-1: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
30. AllergyIntolerance.recordedDate
Control0..1
TypedateTime
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Invariantsuds-plus-all-2: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
32. AllergyIntolerance.recorder
34. AllergyIntolerance.recorder.display
Control0..0
36. AllergyIntolerance.asserter
38. AllergyIntolerance.asserter.display
Control0..0
40. AllergyIntolerance.lastOccurrence
Invariantsuds-plus-all-3: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
42. AllergyIntolerance.note
Control0..0
44. AllergyIntolerance.reaction
Control0..*
Must Supporttrue
46. AllergyIntolerance.reaction.manifestation
Control1..*
Must Supporttrue
48. AllergyIntolerance.reaction.onset
Invariantsuds-plus-all-4: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
50. AllergyIntolerance.reaction.severity
Control0..1
Must Supporttrue
52. AllergyIntolerance.reaction.note
Control0..0

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

0. AllergyIntolerance
Definition

The UDS+ profile is based on the AllergyIntolerance resource and establishes the core elements, extensions, vocabularies and value sets for representing AllergyIntolerance for UDS+ program.


Risk of harmful or undesirable, physiological response which is unique to an individual and associated with exposure to a substance.

ShortDe-Identified UDS Plus AllergyIntoleranceAllergy 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.

Control0..*
Is Modifierfalse
Summaryfalse
Alternate NamesAllergy, Intolerance, Adverse Reaction
Invariantsait-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.id
Definition

De-dentified AllergyIntolerance resource identifier.


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

ShortThe de-identified AllergyIntolerance identifier created by the health center to send data to UDS+ Data ReceiverLogical id of this artifact
Comments

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

Control0..1
Typeidstring
Is Modifierfalse
Must Supporttrue
Summarytrue
4. 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.

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()))
6. 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.

ShortCannot include any text in the resource as part of the de-identified data.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.

Control0..01
TypeNarrative
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesnarrative, html, xhtml, display
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
8. 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.

ShortCannot include any contained resources in the resource as part of the de-identified data.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.

Control0..0*
TypeResource
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesinline resources, anonymous resources, contained resources
10. 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).

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. AllergyIntolerance.clinicalStatus
Definition

The clinical status of the allergy or intolerance.

Shortactive | 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.

Control0..1
This element is affected by the following invariants: ait-1, ait-2
BindingThe codes SHALL be taken from AllergyIntoleranceClinicalStatusCodeshttp://hl7.org/fhir/ValueSet/allergyintolerance-clinical|4.0.1
(required to http://hl7.org/fhir/ValueSet/allergyintolerance-clinical|4.0.1)

The clinical status of the allergy or intolerance.

TypeCodeableConcept
Is Modifiertrue 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 Supporttrue
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. AllergyIntolerance.verificationStatus
Definition

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

Shortunconfirmed | 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.

Control0..1
This element is affected by the following invariants: ait-1, ait-2
BindingThe codes SHALL be taken from AllergyIntoleranceVerificationStatusCodeshttp://hl7.org/fhir/ValueSet/allergyintolerance-verification|4.0.1
(required to http://hl7.org/fhir/ValueSet/allergyintolerance-verification|4.0.1)

Assertion about certainty associated with a propensity, or potential risk, of a reaction to the identified substance.

TypeCodeableConcept
Is Modifiertrue 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 Supporttrue
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
16. AllergyIntolerance.type
Definition

Identification of the underlying physiological mechanism for the reaction risk.

Shortallergy | 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.

Control0..1
BindingThe codes SHALL be taken from AllergyIntoleranceTypehttp://hl7.org/fhir/ValueSet/allergy-intolerance-type|4.0.1
(required to http://hl7.org/fhir/ValueSet/allergy-intolerance-type|4.0.1)

Identification of the underlying physiological mechanism for a Reaction Risk.

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

Category of the identified substance.

Shortfood | 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.

Control0..*
BindingThe codes SHALL be taken from AllergyIntoleranceCategoryhttp://hl7.org/fhir/ValueSet/allergy-intolerance-category|4.0.1
(required to http://hl7.org/fhir/ValueSet/allergy-intolerance-category|4.0.1)

Category of an identified substance associated with allergies or intolerances.

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Alternate NamesCategory, Type, Reaction Type, Class
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
20. AllergyIntolerance.criticality
Definition

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

Shortlow | 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.

Control0..1
BindingThe codes SHALL be taken from AllergyIntoleranceCriticalityhttp://hl7.org/fhir/ValueSet/allergy-intolerance-criticality|4.0.1
(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.

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

ShortCode 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.

Control10..1
BindingUnless 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
(extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1186.8)

The set of codes indicating the allergy or intolerance


Type of the substance/product, allergy or intolerance condition, or negation/exclusion codes for reporting no known allergies.

TypeCodeableConcept
Is Modifierfalse
Must Supporttrue
Summarytrue
Alternate NamesCode
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
24. AllergyIntolerance.patient
Definition

The patient who has the allergy or intolerance.

ShortWho the sensitivity is for
Control1..1
TypeReference(De-Identified UDS Plus Patient, Patient)
Is Modifierfalse
Must Supporttrue
Summarytrue
Alternate NamesPatient
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
26. AllergyIntolerance.patient.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

ShortText alternative for the resource
Comments

This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

Control0..01
Typestring
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
28. AllergyIntolerance.onset[x]
Definition

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

ShortWhen allergy or intolerance was identified
Control0..1
TypeChoice of: dateTime, Age, string, Period, Range
[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 TypesNo must-support rules about the choice of types/profiles
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
uds-plus-all-1: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
30. AllergyIntolerance.recordedDate
Definition

The recordedDate represents when this particular AllergyIntolerance record was created in the system, which is often a system-generated date.

ShortDate first version of the resource instance was recorded
Control0..1
TypedateTime
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
uds-plus-all-2: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
32. AllergyIntolerance.lastOccurrence
Definition

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

ShortDate(/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.

Control0..1
TypedateTime
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
uds-plus-all-3: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
34. AllergyIntolerance.note
Definition

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

ShortAdditional 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.

Control0..0*
TypeAnnotation
Is Modifierfalse
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
36. AllergyIntolerance.reaction
Definition

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

ShortAdverse Reaction Events linked to exposure to substance
Control0..*
TypeBackboneElement
Is Modifierfalse
Must Supporttrue
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
38. 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).

ShortExtensions that cannot be ignored even if unrecognized
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
TypeExtension
Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
Summarytrue
Requirements

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

Alternate Namesextensions, user content, modifiers
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
40. AllergyIntolerance.reaction.manifestation
Definition

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

ShortClinical 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.

Control1..*
BindingFor example codes, see SNOMEDCTClinicalFindingshttp://hl7.org/fhir/ValueSet/clinical-findings
(example to http://hl7.org/fhir/ValueSet/clinical-findings)

Clinical symptoms and/or signs that are observed or associated with an Adverse Reaction Event.

TypeCodeableConcept
Is Modifierfalse
Must Supporttrue
Summaryfalse
Alternate NamesSymptoms, Signs
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
42. AllergyIntolerance.reaction.onset
Definition

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

ShortDate(/time) when manifestations showed
Control0..1
TypedateTime
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summaryfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
uds-plus-all-4: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
44. AllergyIntolerance.reaction.severity
Definition

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

Shortmild | 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.

Control0..1
BindingThe codes SHALL be taken from AllergyIntoleranceSeverityhttp://hl7.org/fhir/ValueSet/reaction-event-severity|4.0.1
(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.

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

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

ShortText 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.

Control0..0*
TypeAnnotation
Is Modifierfalse
Summaryfalse
Invariantsele-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 found here

0. AllergyIntolerance
Definition

The UDS+ profile is based on the AllergyIntolerance resource and establishes the core elements, extensions, vocabularies and value sets for representing AllergyIntolerance for UDS+ program.

ShortDe-Identified UDS Plus AllergyIntolerance
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.

Control0..*
Is Modifierfalse
Summaryfalse
Alternate NamesAllergy, Intolerance, Adverse Reaction
Invariantsait-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

De-dentified AllergyIntolerance resource identifier.

ShortThe de-identified AllergyIntolerance identifier created by the health center to send data to UDS+ Data Receiver
Comments

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

Control0..1
Typeid
Is Modifierfalse
Must Supporttrue
Summarytrue
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.

ShortMetadata about the resource
Control0..1
TypeMeta
Is Modifierfalse
Summarytrue
Invariantsele-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.

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()))
8. AllergyIntolerance.language
Definition

The base language in which the resource is written.

ShortLanguage of the resource content
Comments

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

Control0..1
BindingThe codes SHOULD be taken from CommonLanguages
(preferred to http://hl7.org/fhir/ValueSet/languages)

A human language.

Additional BindingsPurpose
AllLanguagesMax Binding
Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summaryfalse
Invariantsele-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.

ShortCannot include any text in the resource as part of the de-identified data.
Comments

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

Control0..0
TypeNarrative
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesnarrative, html, xhtml, display
Invariantsele-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.

ShortCannot include any contained resources in the resource as part of the de-identified data.
Comments

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

Control0..0
TypeResource
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesinline 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.

ShortAdditional content defined by implementations
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
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())
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).

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())
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.

ShortExternal 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.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..*
TypeIdentifier
Is Modifierfalse
Summarytrue
Requirements

Allows identification of the AllergyIntolerance as it is known by various participating systems and in a way that remains consistent across servers.

Invariantsele-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.

Shortactive | 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.

Control0..1
This element is affected by the following invariants: ait-1, ait-2
BindingThe codes SHALL be taken from AllergyIntoleranceClinicalStatusCodes
(required to http://hl7.org/fhir/ValueSet/allergyintolerance-clinical|4.0.1)

The clinical status of the allergy or intolerance.

TypeCodeableConcept
Is Modifiertrue 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 Supporttrue
Summarytrue
Invariantsele-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).

Shortunconfirmed | 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.

Control0..1
This element is affected by the following invariants: ait-1, ait-2
BindingThe codes SHALL be taken from AllergyIntoleranceVerificationStatusCodes
(required to http://hl7.org/fhir/ValueSet/allergyintolerance-verification|4.0.1)

Assertion about certainty associated with a propensity, or potential risk, of a reaction to the identified substance.

TypeCodeableConcept
Is Modifiertrue 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 Supporttrue
Summarytrue
Invariantsele-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.

Shortallergy | 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.

Control0..1
BindingThe 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.

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Alternate NamesCategory, Class
Invariantsele-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.

Shortfood | 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.

Control0..*
BindingThe 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.

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Alternate NamesCategory, Type, Reaction Type, Class
Invariantsele-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.

Shortlow | 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.

Control0..1
BindingThe 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.

Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Alternate NamesSeverity, Seriousness, Contra-indication, Risk
Invariantsele-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.

ShortCode 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.

Control1..1
BindingUnless 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)

The set of codes indicating the allergy or intolerance

TypeCodeableConcept
Is Modifierfalse
Must Supporttrue
Summarytrue
Alternate NamesCode
Invariantsele-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.

ShortWho the sensitivity is for
Control1..1
TypeReference(De-Identified UDS Plus Patient)
Is Modifierfalse
Must Supporttrue
Summarytrue
Alternate NamesPatient
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
34. AllergyIntolerance.patient.id
Definition

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

ShortUnique id for inter-element referencing
Control0..1
Typestring
Is Modifierfalse
XML FormatIn the XML format, this property is represented as an attribute.
Summaryfalse
36. AllergyIntolerance.patient.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

ShortAdditional content defined by implementations
Comments

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Control0..*
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 AllergyIntolerance.patient.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 38. AllergyIntolerance.patient.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.

    Control0..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
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    40. AllergyIntolerance.patient.type
    Definition

    The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent.

    The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).

    ShortType the reference refers to (e.g. "Patient")
    Comments

    This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified.

    Control0..1
    BindingUnless not suitable, these codes SHALL be taken from ResourceType
    (extensible to http://hl7.org/fhir/ValueSet/resource-types)

    Aa resource (or, for logical models, the URI of the logical model).

    Typeuri
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    42. AllergyIntolerance.patient.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
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    44. AllergyIntolerance.patient.display
    Definition

    Plain text narrative that identifies the resource in addition to the resource reference.

    ShortText alternative for the resource
    Comments

    This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

    Control0..0
    Typestring
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supportfalse
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    46. AllergyIntolerance.encounter
    Definition

    The encounter when the allergy or intolerance was asserted.

    ShortEncounter when the allergy or intolerance was asserted
    Control0..1
    TypeReference(Encounter)
    Is Modifierfalse
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    48. AllergyIntolerance.encounter.id
    Definition

    Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

    ShortUnique id for inter-element referencing
    Control0..1
    Typestring
    Is Modifierfalse
    XML FormatIn the XML format, this property is represented as an attribute.
    Summaryfalse
    50. AllergyIntolerance.encounter.extension
    Definition

    May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

    ShortAdditional content defined by implementations
    Comments

    There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

    Control0..*
    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 AllergyIntolerance.encounter.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 52. AllergyIntolerance.encounter.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.

      Control0..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
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      54. AllergyIntolerance.encounter.type
      Definition

      The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent.

      The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).

      ShortType the reference refers to (e.g. "Patient")
      Comments

      This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified.

      Control0..1
      BindingUnless not suitable, these codes SHALL be taken from ResourceType
      (extensible to http://hl7.org/fhir/ValueSet/resource-types)

      Aa resource (or, for logical models, the URI of the logical model).

      Typeuri
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      56. AllergyIntolerance.encounter.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
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      58. AllergyIntolerance.encounter.display
      Definition

      Plain text narrative that identifies the resource in addition to the resource reference.

      ShortText alternative for the resource
      Comments

      This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

      Control0..0
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supportfalse
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      60. AllergyIntolerance.onset[x]
      Definition

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

      ShortWhen allergy or intolerance was identified
      Control0..1
      TypeChoice of: dateTime, 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 TypesNo must-support rules about the choice of types/profiles
      Summaryfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      uds-plus-all-1: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
      62. AllergyIntolerance.recordedDate
      Definition

      The recordedDate represents when this particular AllergyIntolerance record was created in the system, which is often a system-generated date.

      ShortDate first version of the resource instance was recorded
      Control0..1
      TypedateTime
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Summaryfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      uds-plus-all-2: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
      64. AllergyIntolerance.recorder
      Definition

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

      ShortWho recorded the sensitivity
      Control0..1
      TypeReference(Practitioner, PractitionerRole, Patient, RelatedPerson)
      Is Modifierfalse
      Summaryfalse
      Alternate NamesAuthor
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      66. AllergyIntolerance.recorder.id
      Definition

      Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

      ShortUnique id for inter-element referencing
      Control0..1
      Typestring
      Is Modifierfalse
      XML FormatIn the XML format, this property is represented as an attribute.
      Summaryfalse
      68. AllergyIntolerance.recorder.extension
      Definition

      May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

      ShortAdditional content defined by implementations
      Comments

      There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

      Control0..*
      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 AllergyIntolerance.recorder.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 70. AllergyIntolerance.recorder.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.

        Control0..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
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        72. AllergyIntolerance.recorder.type
        Definition

        The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent.

        The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).

        ShortType the reference refers to (e.g. "Patient")
        Comments

        This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified.

        Control0..1
        BindingUnless not suitable, these codes SHALL be taken from ResourceType
        (extensible to http://hl7.org/fhir/ValueSet/resource-types)

        Aa resource (or, for logical models, the URI of the logical model).

        Typeuri
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        74. AllergyIntolerance.recorder.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
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        76. AllergyIntolerance.recorder.display
        Definition

        Plain text narrative that identifies the resource in addition to the resource reference.

        ShortText alternative for the resource
        Comments

        This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

        Control0..0
        Typestring
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        78. AllergyIntolerance.asserter
        Definition

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

        ShortSource of the information about the allergy
        Comments

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

        Control0..1
        TypeReference(Patient, RelatedPerson, Practitioner, PractitionerRole)
        Is Modifierfalse
        Summarytrue
        Alternate NamesSource, Informant
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        80. AllergyIntolerance.asserter.id
        Definition

        Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

        ShortUnique id for inter-element referencing
        Control0..1
        Typestring
        Is Modifierfalse
        XML FormatIn the XML format, this property is represented as an attribute.
        Summaryfalse
        82. AllergyIntolerance.asserter.extension
        Definition

        May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

        ShortAdditional content defined by implementations
        Comments

        There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

        Control0..*
        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 AllergyIntolerance.asserter.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ url
        • 84. AllergyIntolerance.asserter.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.

          Control0..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
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          86. AllergyIntolerance.asserter.type
          Definition

          The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent.

          The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).

          ShortType the reference refers to (e.g. "Patient")
          Comments

          This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified.

          Control0..1
          BindingUnless not suitable, these codes SHALL be taken from ResourceType
          (extensible to http://hl7.org/fhir/ValueSet/resource-types)

          Aa resource (or, for logical models, the URI of the logical model).

          Typeuri
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          88. AllergyIntolerance.asserter.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
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          90. AllergyIntolerance.asserter.display
          Definition

          Plain text narrative that identifies the resource in addition to the resource reference.

          ShortText alternative for the resource
          Comments

          This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

          Control0..0
          Typestring
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          92. AllergyIntolerance.lastOccurrence
          Definition

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

          ShortDate(/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.

          Control0..1
          TypedateTime
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          uds-plus-all-3: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
          94. AllergyIntolerance.note
          Definition

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

          ShortAdditional 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.

          Control0..0
          TypeAnnotation
          Is Modifierfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          96. AllergyIntolerance.reaction
          Definition

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

          ShortAdverse Reaction Events linked to exposure to substance
          Control0..*
          TypeBackboneElement
          Is Modifierfalse
          Must Supporttrue
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          98. 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.

          ShortUnique id for inter-element referencing
          Control0..1
          Typestring
          Is Modifierfalse
          XML FormatIn the XML format, this property is represented as an attribute.
          Summaryfalse
          100. 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.

          ShortAdditional content defined by implementations
          Comments

          There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

          Control0..*
          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())
          102. 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).

          ShortExtensions that cannot be ignored even if unrecognized
          Comments

          There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

          Control0..*
          TypeExtension
          Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
          Summarytrue
          Requirements

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

          Alternate Namesextensions, user content, modifiers
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
          104. 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.

          ShortSpecific 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'.

          Control0..1
          BindingFor example codes, see SubstanceCode
          (example to http://hl7.org/fhir/ValueSet/substance-code)

          Codes defining the type of the substance (including pharmaceutical products).

          TypeCodeableConcept
          Is Modifierfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          106. AllergyIntolerance.reaction.manifestation
          Definition

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

          ShortClinical 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.

          Control1..*
          BindingFor example codes, see SNOMEDCTClinicalFindings
          (example to http://hl7.org/fhir/ValueSet/clinical-findings)

          Clinical symptoms and/or signs that are observed or associated with an Adverse Reaction Event.

          TypeCodeableConcept
          Is Modifierfalse
          Must Supporttrue
          Summaryfalse
          Alternate NamesSymptoms, Signs
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          108. AllergyIntolerance.reaction.description
          Definition

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

          ShortDescription 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.

          Control0..1
          Typestring
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summaryfalse
          Alternate NamesNarrative, Text
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          110. AllergyIntolerance.reaction.onset
          Definition

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

          ShortDate(/time) when manifestations showed
          Control0..1
          TypedateTime
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          uds-plus-all-4: All dateTime data elements should be truncated to a year only for de-identified resources. ($this is DateTime implies $this.toString().length() = 4)
          112. AllergyIntolerance.reaction.severity
          Definition

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

          Shortmild | 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.

          Control0..1
          BindingThe 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.

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

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

          ShortHow the subject was exposed to the substance
          Comments

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

          Control0..1
          BindingFor example codes, see SNOMEDCTRouteCodes
          (example to http://hl7.org/fhir/ValueSet/route-codes)

          A coded concept describing the route or physiological path of administration of a therapeutic agent into or onto the body of a subject.

          TypeCodeableConcept
          Is Modifierfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          116. AllergyIntolerance.reaction.note
          Definition

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

          ShortText 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.

          Control0..0
          TypeAnnotation
          Is Modifierfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))