Implementation Guide for Astacus project
0.0.1 - ci-build France flag

Implementation Guide for Astacus project - Local Development build (v0.0.1) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

Resource Profile: AstacusTumorMarkerTest - Detailed Descriptions

Draft as of 2024-05-23 Maturity Level: 4

Definitions for the astacus-tumor-marker-test resource profile.

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

0. Observation
2. Observation.extension:relatedCondition
Slice NamerelatedCondition
Definition

Associates the tumor marker test with a condition, if one exists. Condition can be given by a reference or a code. In the case of a screening test such as prostate-specific antigen (PSA), there may be no existing condition to reference.

ShortCondition associated with this test.
Control0..*
TypeExtension(Related Condition Extension) (Extension Type: Choice of: CodeableConcept, Reference(Condition))
Must Supporttrue
4. Observation.code
BindingUnless not suitable, these codes SHALL be taken from Tumor Marker Test Value Set
(extensible to http://hl7.org/fhir/us/mcode/ValueSet/mcode-tumor-marker-test-vs)
6. Observation.effective[x]
TypeChoice of: dateTime, Period, Timing, instant
[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
8. Observation.value[x]
Control1..?
TypeChoice of: Quantity, CodeableConcept, string, Ratio, dateTime, boolean, SampledData, Period, integer, time, 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
10. Observation.specimen
TypeReference(Astacus Human Specimen Profile)
Must Supporttrue

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

0. Observation
Definition

Measurements and simple assertions made about a patient, device or other subject.

ShortMeasurements and simple assertions
Comments

Used for simple observations such as device measurements, laboratory atomic results, vital signs, height, weight, smoking status, comments, etc. Other resources are used to provide context for observations such as laboratory reports, etc.

Control0..*
Alternate NamesVital Signs, Measurement, Results, Tests
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.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-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-6: A resource should have narrative for robust management (text.`div`.exists())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
2. Observation.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
This element is affected by the following invariants: ele-1
Typeuri
Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. Observation.extension:relatedCondition
Slice NamerelatedCondition
Definition

Associates the tumor marker test with a condition, if one exists. Condition can be given by a reference or a code. In the case of a screening test such as prostate-specific antigen (PSA), there may be no existing condition to reference.

ShortCondition associated with this test.
Control0..*
This element is affected by the following invariants: ele-1
TypeExtension(Related Condition Extension) (Extension Type: Choice of: CodeableConcept, Reference(Condition))
Must Supporttrue
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())
6. Observation.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..*
This element is affected by the following invariants: ele-1
TypeExtension
Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Standard StatusNormative (from Normative)
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())
SlicingThis element introduces a set of slices on Observation.modifierExtension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 8. Observation.status
    Definition

    The status of the result value.

    Shortregistered | preliminary | final | amended +
    Comments

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

    Control1..1
    This element is affected by the following invariants: ele-1
    BindingThe codes SHALL be taken from ObservationStatushttp://hl7.org/fhir/ValueSet/observation-status|4.0.1
    (required to http://hl7.org/fhir/ValueSet/observation-status|4.0.1)

    Codes providing the status of an observation.

    Typecode
    Is Modifiertrue because This element is labeled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Summarytrue
    Requirements

    Need to track the status of individual results. Some results are finalized before the whole report is finalized.

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

    A code that classifies the general type of observation being made.

    ShortClassification of type of observation
    Comments

    In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

    Control10..*
    This element is affected by the following invariants: ele-1
    BindingThe codes SHOULD be taken from ObservationCategoryCodeshttp://hl7.org/fhir/ValueSet/observation-category
    (preferred to http://hl7.org/fhir/ValueSet/observation-category)

    Codes for high level observation categories.

    TypeCodeableConcept
    Must Supporttrue
    Requirements

    Used for filtering what observations are retrieved and displayed.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    SlicingThis element introduces a set of slices on Observation.category. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • pattern @ $this
    • 12. Observation.category:Laboratory
      Slice NameLaboratory
      Definition

      A code that classifies the general type of observation being made.

      ShortClassification of type of observation
      Comments

      In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

      Control10..1*
      This element is affected by the following invariants: ele-1
      BindingThe codes SHOULD be taken from ObservationCategoryCodeshttp://hl7.org/fhir/ValueSet/observation-category
      (preferred to http://hl7.org/fhir/ValueSet/observation-category)

      Codes for high level observation categories.

      TypeCodeableConcept
      Must Supporttrue
      Requirements

      Used for filtering what observations are retrieved and displayed.

      Pattern Value{
        "coding" : [{
          "system" : "http://terminology.hl7.org/CodeSystem/observation-category",
          "code" : "laboratory"
        }]
      }
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      14. Observation.code
      Definition

      The test that was performed. A LOINC SHALL be used if the concept is present in LOINC.


      Describes what was observed. Sometimes this is called the observation "name".

      ShortLaboratory Test NameType of observation (code / type)
      Comments

      The typical patterns for codes are: 1) a LOINC code either as a translation from a "local" code or as a primary code, or 2) a local code only if no suitable LOINC exists, or 3) both the local and the LOINC translation. Systems SHALL be capable of sending the local code if one exists. When using LOINC , Use either the SHORTNAME or LONG_COMMON_NAME field for the display.


      All code-value and, if present, component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

      Control1..1
      This element is affected by the following invariants: ele-1
      BindingUnless not suitable, these codes SHALL be taken from For example codes, see Tumor Marker Test Value Sethttp://hl7.org/fhir/ValueSet/observation-codes
      (extensible to http://hl7.org/fhir/us/mcode/ValueSet/mcode-tumor-marker-test-vs)
      TypeCodeableConcept
      Must Supporttrue
      Summarytrue
      Requirements

      Knowing what kind of observation is being made is essential to understanding the observation.

      Alternate NamesName, Test Name, Observation Identifier
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      16. Observation.subject
      Definition

      Patient whose test result is recorded.


      The patient, or group of patients, location, or device this observation is about and into whose record the observation is placed. If the actual focus of the observation is different from the subject (or a sample of, part, or region of the subject), the focus element or the code itself specifies the actual focus of the observation.

      ShortWho and/or what the observation is about
      Comments

      One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

      Control10..1
      This element is affected by the following invariants: ele-1
      TypeReference(Astacus Cancer Patient Profile, Patient, Group, Device, Location)
      Must Supporttrue
      Summarytrue
      Requirements

      Observations have no value if you don't know who or what they're about.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
      18. Observation.effective[x]
      Definition

      For lab tests this is the specimen collection date. For Ask at Order Entry Questions (AOE)'s this is the date the question was asked.


      The time or time-period the observed value is asserted as being true. For biological subjects - e.g. human patients - this is usually called the "physiologically relevant time". This is usually either the time of the procedure or of specimen collection, but very often the source of the date/time is not known, only the date/time itself.

      ShortClinically relevant time/time-period for observation
      Comments

      At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

      Control0..1
      This element is affected by the following invariants: ele-1
      TypeChoice of: dateTime, Period, Timing, instant
      [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
      Summarytrue
      Requirements

      Knowing when an observation was deemed true is important to its relevance as well as determining trends.

      Alternate NamesOccurrence
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      20. Observation.value[x]
      Definition

      The Laboratory result value. If a coded value, the valueCodeableConcept.code SHOULD be selected from SNOMED CT if the concept exists. If a numeric value, valueQuantity.code SHALL be selected from UCUM. A FHIR UCUM Codes value set that defines all UCUM codes is in the FHIR specification.


      The information determined as a result of making the observation, if the information has a simple value.

      ShortResult ValueActual result
      Comments

      An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

      Control10..1
      This element is affected by the following invariants: ele-1, obs-7
      TypeChoice of: Quantity, CodeableConcept, string, Ratio, dateTime, boolean, SampledData, Period, integer, time, 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
      Summarytrue
      Requirements

      An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

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

      Provides a reason why the expected value in the element Observation.value[x] is missing.

      ShortWhy the result is missing
      Comments

      Null or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "specimen unsatisfactory".

      The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Note that an observation may only be reported if there are values to report. For example differential cell counts values may be reported only when > 0. Because of these options, use-case agreements are required to interpret general observations for null or exceptional values.

      Control0..1
      This element is affected by the following invariants: ele-1, obs-6
      BindingUnless not suitable, these codes SHALL be taken from DataAbsentReasonhttp://hl7.org/fhir/ValueSet/data-absent-reason
      (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

      Codes specifying why the result (Observation.value[x]) is missing.

      TypeCodeableConcept
      Must Supporttrue
      Requirements

      For many results it is necessary to handle exceptional values in measurements.

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

      The specimen that was used when this observation was made.

      ShortSpecimen used for this observation
      Comments

      Should only be used if not implicit in code found in Observation.code. Observations are not made on specimens themselves; they are made on a subject, but in many cases by the means of a specimen. Note that although specimens are often involved, they are not always tracked and reported explicitly. Also note that observation resources may be used in contexts that track the specimen explicitly (e.g. Diagnostic Report).

      Control0..1
      This element is affected by the following invariants: ele-1
      TypeReference(Astacus Human Specimen Profile, Specimen)
      Must Supporttrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))

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

      0. Observation
      Definition

      Measurements and simple assertions made about a patient, device or other subject.

      ShortMeasurements and simple assertions
      Comments

      Used for simple observations such as device measurements, laboratory atomic results, vital signs, height, weight, smoking status, comments, etc. Other resources are used to provide context for observations such as laboratory reports, etc.

      Control0..*
      Alternate NamesVital Signs, Measurement, Results, Tests
      Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.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-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-6: A resource should have narrative for robust management (text.`div`.exists())
      dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
      obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
      obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
      2. Observation.id
      Definition

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

      ShortLogical 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
      Typeid
      Summarytrue
      4. Observation.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
      This element is affected by the following invariants: ele-1
      TypeMeta
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      6. Observation.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
      This element is affected by the following invariants: ele-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. Observation.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
      This element is affected by the following invariants: ele-1
      BindingThe codes SHOULD be taken from CommonLanguages
      (preferred to http://hl7.org/fhir/ValueSet/languages)

      A human language.

      Additional BindingsPurpose
      AllLanguagesMax Binding
      Typecode
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      10. Observation.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.

      ShortText 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..1
      This element is affected by the following invariants: ele-1
      TypeNarrative
      Alternate Namesnarrative, html, xhtml, display
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      12. Observation.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.

      ShortContained, 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..*
      TypeResource
      Alternate Namesinline resources, anonymous resources, contained resources
      14. Observation.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..*
      This element is affected by the following invariants: ele-1
      TypeExtension
      Standard StatusNormative (from Normative)
      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 Observation.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 16. Observation.extension:relatedCondition
        Slice NamerelatedCondition
        Definition

        Associates the tumor marker test with a condition, if one exists. Condition can be given by a reference or a code. In the case of a screening test such as prostate-specific antigen (PSA), there may be no existing condition to reference.

        ShortCondition associated with this test.
        Control0..*
        This element is affected by the following invariants: ele-1
        TypeExtension(Related Condition Extension) (Extension Type: Choice of: CodeableConcept, Reference(Condition))
        Must Supporttrue
        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. Observation.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..*
        This element is affected by the following invariants: ele-1
        TypeExtension
        Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
        Standard StatusNormative (from Normative)
        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())
        SlicingThis element introduces a set of slices on Observation.modifierExtension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ url
        • 20. Observation.identifier
          Definition

          A unique identifier assigned to this observation.

          ShortBusiness Identifier for observation
          NoteThis is a business identifier, not a resource identifier (see discussion)
          Control0..*
          This element is affected by the following invariants: ele-1
          TypeIdentifier
          Summarytrue
          Requirements

          Allows observations to be distinguished and referenced.

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

          A plan, proposal or order that is fulfilled in whole or in part by this event. For example, a MedicationRequest may require a patient to have laboratory test performed before it is dispensed.

          ShortFulfills plan, proposal or order
          Comments

          References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

          Control0..*
          This element is affected by the following invariants: ele-1
          TypeReference(CarePlan, DeviceRequest, ImmunizationRecommendation, MedicationRequest, NutritionOrder, ServiceRequest)
          Summarytrue
          Requirements

          Allows tracing of authorization for the event and tracking whether proposals/recommendations were acted upon.

          Alternate NamesFulfills
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
          24. Observation.partOf
          Definition

          A larger event of which this particular Observation is a component or step. For example, an observation as part of a procedure.

          ShortPart of referenced event
          Comments

          To link an Observation to an Encounter use encounter. See the Notes below for guidance on referencing another Observation.

          Control0..*
          This element is affected by the following invariants: ele-1
          TypeReference(MedicationAdministration, MedicationDispense, MedicationStatement, Procedure, Immunization, ImagingStudy)
          Summarytrue
          Alternate NamesContainer
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
          26. Observation.status
          Definition

          The status of the result value.

          Shortregistered | preliminary | final | amended +
          Comments

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

          Control1..1
          This element is affected by the following invariants: ele-1
          BindingThe codes SHALL be taken from ObservationStatus
          (required to http://hl7.org/fhir/ValueSet/observation-status|4.0.1)

          Codes providing the status of an observation.

          Typecode
          Is Modifiertrue because This element is labeled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Must Supporttrue
          Summarytrue
          Requirements

          Need to track the status of individual results. Some results are finalized before the whole report is finalized.

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

          A code that classifies the general type of observation being made.

          ShortClassification of type of observation
          Comments

          In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

          Control1..*
          This element is affected by the following invariants: ele-1
          BindingThe codes SHOULD be taken from ObservationCategoryCodes
          (preferred to http://hl7.org/fhir/ValueSet/observation-category)

          Codes for high level observation categories.

          TypeCodeableConcept
          Must Supporttrue
          Requirements

          Used for filtering what observations are retrieved and displayed.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          SlicingThis element introduces a set of slices on Observation.category. The slices areUnordered and Open, and can be differentiated using the following discriminators:
          • pattern @ $this
          • 30. Observation.category:Laboratory
            Slice NameLaboratory
            Definition

            A code that classifies the general type of observation being made.

            ShortClassification of type of observation
            Comments

            In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

            Control1..1
            This element is affected by the following invariants: ele-1
            BindingThe codes SHOULD be taken from ObservationCategoryCodes
            (preferred to http://hl7.org/fhir/ValueSet/observation-category)

            Codes for high level observation categories.

            TypeCodeableConcept
            Must Supporttrue
            Requirements

            Used for filtering what observations are retrieved and displayed.

            Pattern Value{
              "coding" : [{
                "system" : "http://terminology.hl7.org/CodeSystem/observation-category",
                "code" : "laboratory"
              }]
            }
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            32. Observation.code
            Definition

            The test that was performed. A LOINC SHALL be used if the concept is present in LOINC.

            ShortLaboratory Test Name
            Comments

            The typical patterns for codes are: 1) a LOINC code either as a translation from a "local" code or as a primary code, or 2) a local code only if no suitable LOINC exists, or 3) both the local and the LOINC translation. Systems SHALL be capable of sending the local code if one exists. When using LOINC , Use either the SHORTNAME or LONG_COMMON_NAME field for the display.

            Control1..1
            This element is affected by the following invariants: ele-1
            BindingUnless not suitable, these codes SHALL be taken from Tumor Marker Test Value Set
            (extensible to http://hl7.org/fhir/us/mcode/ValueSet/mcode-tumor-marker-test-vs)
            TypeCodeableConcept
            Must Supporttrue
            Summarytrue
            Requirements

            Knowing what kind of observation is being made is essential to understanding the observation.

            Alternate NamesName, Test Name, Observation Identifier
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            34. Observation.subject
            Definition

            Patient whose test result is recorded.

            ShortWho and/or what the observation is about
            Comments

            One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

            Control1..1
            This element is affected by the following invariants: ele-1
            TypeReference(Astacus Cancer Patient Profile)
            Must Supporttrue
            Summarytrue
            Requirements

            Observations have no value if you don't know who or what they're about.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
            36. Observation.focus
            Definition

            The actual focus of an observation when it is not the patient of record representing something or someone associated with the patient such as a spouse, parent, fetus, or donor. For example, fetus observations in a mother's record. The focus of an observation could also be an existing condition, an intervention, the subject's diet, another observation of the subject, or a body structure such as tumor or implanted device. An example use case would be using the Observation resource to capture whether the mother is trained to change her child's tracheostomy tube. In this example, the child is the patient of record and the mother is the focus.

            ShortWhat the observation is about, when it is not about the subject of record
            Comments

            Typically, an observation is made about the subject - a patient, or group of patients, location, or device - and the distinction between the subject and what is directly measured for an observation is specified in the observation code itself ( e.g., "Blood Glucose") and does not need to be represented separately using this element. Use specimen if a reference to a specimen is required. If a code is required instead of a resource use either bodysite for bodysites or the standard extension focusCode.

            Control0..*
            This element is affected by the following invariants: ele-1
            TypeReference(Resource)
            Summarytrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
            38. Observation.encounter
            Definition

            The healthcare event (e.g. a patient and healthcare provider interaction) during which this observation is made.

            ShortHealthcare event during which this observation is made
            Comments

            This will typically be the encounter the event occurred within, but some events may be initiated prior to or after the official completion of an encounter but still be tied to the context of the encounter (e.g. pre-admission laboratory tests).

            Control0..1
            This element is affected by the following invariants: ele-1
            TypeReference(Encounter)
            Summarytrue
            Requirements

            For some observations it may be important to know the link between an observation and a particular encounter.

            Alternate NamesContext
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
            40. Observation.effective[x]
            Definition

            For lab tests this is the specimen collection date. For Ask at Order Entry Questions (AOE)'s this is the date the question was asked.

            ShortClinically relevant time/time-period for observation
            Comments

            At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

            Control0..1
            This element is affected by the following invariants: ele-1
            TypeChoice of: dateTime, Period
            [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
            Summarytrue
            Requirements

            Knowing when an observation was deemed true is important to its relevance as well as determining trends.

            Alternate NamesOccurrence
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            42. Observation.issued
            Definition

            The date and time this version of the observation was made available to providers, typically after the results have been reviewed and verified.

            ShortDate/Time this version was made available
            Comments

            For Observations that don’t require review and verification, it may be the same as the lastUpdated time of the resource itself. For Observations that do require review and verification for certain updates, it might not be the same as the lastUpdated time of the resource itself due to a non-clinically significant update that doesn’t require the new version to be reviewed and verified again.

            Control0..1
            This element is affected by the following invariants: ele-1
            Typeinstant
            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()))
            44. Observation.performer
            Definition

            Who was responsible for asserting the observed value as "true".

            ShortWho is responsible for the observation
            Comments

            References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

            Control0..*
            This element is affected by the following invariants: ele-1
            TypeReference(Practitioner, PractitionerRole, Organization, CareTeam, Patient, RelatedPerson)
            Summarytrue
            Requirements

            May give a degree of confidence in the observation and also indicates where follow-up questions should be directed.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
            46. Observation.value[x]
            Definition

            The Laboratory result value. If a coded value, the valueCodeableConcept.code SHOULD be selected from SNOMED CT if the concept exists. If a numeric value, valueQuantity.code SHALL be selected from UCUM. A FHIR UCUM Codes value set that defines all UCUM codes is in the FHIR specification.

            ShortResult Value
            Comments

            An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

            Control1..1
            This element is affected by the following invariants: ele-1, obs-7
            TypeChoice of: Quantity, CodeableConcept, string, Ratio
            [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
            Summarytrue
            Requirements

            An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

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

            Provides a reason why the expected value in the element Observation.value[x] is missing.

            ShortWhy the result is missing
            Comments

            Null or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "specimen unsatisfactory".

            The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Note that an observation may only be reported if there are values to report. For example differential cell counts values may be reported only when > 0. Because of these options, use-case agreements are required to interpret general observations for null or exceptional values.

            Control0..1
            This element is affected by the following invariants: ele-1, obs-6
            BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
            (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

            Codes specifying why the result (Observation.value[x]) is missing.

            TypeCodeableConcept
            Must Supporttrue
            Requirements

            For many results it is necessary to handle exceptional values in measurements.

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

            A categorical assessment of an observation value. For example, high, low, normal.

            ShortHigh, low, normal, etc.
            Comments

            Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

            Control0..*
            This element is affected by the following invariants: ele-1
            BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
            (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

            Codes identifying interpretations of observations.

            TypeCodeableConcept
            Requirements

            For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

            Alternate NamesAbnormal Flag
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            52. Observation.note
            Definition

            Comments about the observation or the results.

            ShortComments about the observation
            Comments

            May include general statements about the observation, or statements about significant, unexpected or unreliable results values, or information about its source when relevant to its interpretation.

            Control0..*
            This element is affected by the following invariants: ele-1
            TypeAnnotation
            Requirements

            Need to be able to provide free text additional information.

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

            Indicates the site on the subject's body where the observation was made (i.e. the target site).

            ShortObserved body part
            Comments

            Only used if not implicit in code found in Observation.code. In many systems, this may be represented as a related observation instead of an inline component.

            If the use case requires BodySite to be handled as a separate resource (e.g. to identify and track separately) then use the standard extension bodySite.

            Control0..1
            This element is affected by the following invariants: ele-1
            BindingFor example codes, see SNOMEDCTBodyStructures
            (example to http://hl7.org/fhir/ValueSet/body-site)

            Codes describing anatomical locations. May include laterality.

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

            Indicates the mechanism used to perform the observation.

            ShortHow it was done
            Comments

            Only used if not implicit in code for Observation.code.

            Control0..1
            This element is affected by the following invariants: ele-1
            BindingFor example codes, see ObservationMethods
            (example to http://hl7.org/fhir/ValueSet/observation-methods)

            Methods for simple observations.

            TypeCodeableConcept
            Requirements

            In some cases, method can impact results and is thus used for determining whether results can be compared or determining significance of results.

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

            The specimen that was used when this observation was made.

            ShortSpecimen used for this observation
            Comments

            Should only be used if not implicit in code found in Observation.code. Observations are not made on specimens themselves; they are made on a subject, but in many cases by the means of a specimen. Note that although specimens are often involved, they are not always tracked and reported explicitly. Also note that observation resources may be used in contexts that track the specimen explicitly (e.g. Diagnostic Report).

            Control0..1
            This element is affected by the following invariants: ele-1
            TypeReference(Astacus Human Specimen Profile)
            Must Supporttrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
            60. Observation.device
            Definition

            The device used to generate the observation data.

            Short(Measurement) Device
            Comments

            Note that this is not meant to represent a device involved in the transmission of the result, e.g., a gateway. Such devices may be documented using the Provenance resource where relevant.

            Control0..1
            This element is affected by the following invariants: ele-1
            TypeReference(Device, DeviceMetric)
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
            62. Observation.referenceRange
            Definition

            Guidance on how to interpret the value by comparison to a normal or recommended range. Multiple reference ranges are interpreted as an "OR". In other words, to represent two distinct target populations, two referenceRange elements would be used.

            ShortProvides guide for interpretation
            Comments

            Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this might not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

            Control0..*
            This element is affected by the following invariants: ele-1
            TypeBackboneElement
            Requirements

            Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            obs-3: Must have at least a low or a high or text (low.exists() or high.exists() or text.exists())
            64. Observation.referenceRange.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
            XML FormatIn the XML format, this property is represented as an attribute.
            66. Observation.referenceRange.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..*
            This element is affected by the following invariants: ele-1
            TypeExtension
            Standard StatusNormative (from Normative)
            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 Observation.referenceRange.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
            • value @ url
            • 68. Observation.referenceRange.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..*
              This element is affected by the following invariants: ele-1
              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())
              70. Observation.referenceRange.low
              Definition

              The value of the low bound of the reference range. The low bound of the reference range endpoint is inclusive of the value (e.g. reference range is >=5 - <=9). If the low bound is omitted, it is assumed to be meaningless (e.g. reference range is <=2.3).

              ShortLow Range, if relevant
              Comments

              The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

              Control0..1
              This element is affected by the following invariants: ele-1, obs-3
              TypeQuantity(SimpleQuantity)
              Is Modifierfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              qty-3: If a code for the unit is present, the system SHALL also be present (code.empty() or system.exists())
              sqty-1: The comparator is not used on a SimpleQuantity (comparator.empty())
              72. Observation.referenceRange.high
              Definition

              The value of the high bound of the reference range. The high bound of the reference range endpoint is inclusive of the value (e.g. reference range is >=5 - <=9). If the high bound is omitted, it is assumed to be meaningless (e.g. reference range is >= 2.3).

              ShortHigh Range, if relevant
              Comments

              The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

              Control0..1
              This element is affected by the following invariants: ele-1, obs-3
              TypeQuantity(SimpleQuantity)
              Is Modifierfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              qty-3: If a code for the unit is present, the system SHALL also be present (code.empty() or system.exists())
              sqty-1: The comparator is not used on a SimpleQuantity (comparator.empty())
              74. Observation.referenceRange.type
              Definition

              Codes to indicate the what part of the targeted reference population it applies to. For example, the normal or therapeutic range.

              ShortReference range qualifier
              Comments

              This SHOULD be populated if there is more than one range. If this element is not present then the normal range is assumed.

              Control0..1
              This element is affected by the following invariants: ele-1
              BindingThe codes SHOULD be taken from ObservationReferenceRangeMeaningCodes
              (preferred to http://hl7.org/fhir/ValueSet/referencerange-meaning)

              Code for the meaning of a reference range.

              TypeCodeableConcept
              Requirements

              Need to be able to say what kind of reference range this is - normal, recommended, therapeutic, etc., - for proper interpretation.

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

              Codes to indicate the target population this reference range applies to. For example, a reference range may be based on the normal population or a particular sex or race. Multiple appliesTo are interpreted as an "AND" of the target populations. For example, to represent a target population of African American females, both a code of female and a code for African American would be used.

              ShortReference range population
              Comments

              This SHOULD be populated if there is more than one range. If this element is not present then the normal population is assumed.

              Control0..*
              This element is affected by the following invariants: ele-1
              BindingFor example codes, see ObservationReferenceRangeAppliesToCodes
              (example to http://hl7.org/fhir/ValueSet/referencerange-appliesto)

              Codes identifying the population the reference range applies to.

              TypeCodeableConcept
              Requirements

              Need to be able to identify the target population for proper interpretation.

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

              The age at which this reference range is applicable. This is a neonatal age (e.g. number of weeks at term) if the meaning says so.

              ShortApplicable age range, if relevant
              Comments

              The stated low and high value are assumed to have arbitrarily high precision when it comes to determining which values are in the range. I.e. 1.99 is not in the range 2 -> 3.

              Control0..1
              This element is affected by the following invariants: ele-1
              TypeRange
              Requirements

              Some analytes vary greatly over age.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              rng-2: If present, low SHALL have a lower value than high (low.empty() or high.empty() or (low <= high))
              80. Observation.referenceRange.text
              Definition

              Text based reference range in an observation which may be used when a quantitative range is not appropriate for an observation. An example would be a reference value of "Negative" or a list or table of "normals".

              ShortText based reference range in an observation
              Comments

              Note that FHIR strings SHALL NOT exceed 1MB in size

              Control0..1
              This element is affected by the following invariants: ele-1
              Typestring
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              82. Observation.hasMember
              Definition

              This observation is a group observation (e.g. a battery, a panel of tests, a set of vital sign measurements) that includes the target as a member of the group.

              ShortRelated resource that belongs to the Observation group
              Comments

              When using this element, an observation will typically have either a value or a set of related resources, although both may be present in some cases. For a discussion on the ways Observations can assembled in groups together, see Notes below. Note that a system may calculate results from QuestionnaireResponse into a final score and represent the score as an Observation.

              Control0..*
              This element is affected by the following invariants: ele-1
              TypeReference(Observation, QuestionnaireResponse, MolecularSequence)
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
              84. Observation.derivedFrom
              Definition

              The target resource that represents a measurement from which this observation value is derived. For example, a calculated anion gap or a fetal measurement based on an ultrasound image.

              ShortRelated measurements the observation is made from
              Comments

              All the reference choices that are listed in this element can represent clinical observations and other measurements that may be the source for a derived value. The most common reference will be another Observation. For a discussion on the ways Observations can assembled in groups together, see Notes below.

              Control0..*
              This element is affected by the following invariants: ele-1
              TypeReference(DocumentReference, ImagingStudy, Media, QuestionnaireResponse, Observation, MolecularSequence)
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ref-1: SHALL have a contained resource if a local reference is provided (reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids')))
              86. Observation.component
              Definition

              Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

              ShortComponent results
              Comments

              For a discussion on the ways Observations can be assembled in groups together see Notes below.

              Control0..*
              This element is affected by the following invariants: ele-1
              TypeBackboneElement
              Summarytrue
              Requirements

              Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              88. Observation.component.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
              XML FormatIn the XML format, this property is represented as an attribute.
              90. Observation.component.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..*
              This element is affected by the following invariants: ele-1
              TypeExtension
              Standard StatusNormative (from Normative)
              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 Observation.component.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
              • value @ url
              • 92. Observation.component.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..*
                This element is affected by the following invariants: ele-1
                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())
                94. Observation.component.code
                Definition

                Describes what was observed. Sometimes this is called the observation "code".

                ShortType of component observation (code / type)
                Comments

                All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

                Control1..1
                This element is affected by the following invariants: ele-1
                BindingFor example codes, see LOINCCodes
                (example to http://hl7.org/fhir/ValueSet/observation-codes)

                Codes identifying names of simple observations.

                TypeCodeableConcept
                Summarytrue
                Requirements

                Knowing what kind of observation is being made is essential to understanding the observation.

                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                96. Observation.component.value[x]
                Definition

                The information determined as a result of making the observation, if the information has a simple value.

                ShortActual component result
                Comments

                Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

                Control0..1
                This element is affected by the following invariants: ele-1
                TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
                [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
                Summarytrue
                Requirements

                An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

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

                Provides a reason why the expected value in the element Observation.component.value[x] is missing.

                ShortWhy the component result is missing
                Comments

                "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

                The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

                Control0..1
                This element is affected by the following invariants: ele-1, obs-6
                BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
                (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

                Codes specifying why the result (Observation.value[x]) is missing.

                TypeCodeableConcept
                Requirements

                For many results it is necessary to handle exceptional values in measurements.

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

                A categorical assessment of an observation value. For example, high, low, normal.

                ShortHigh, low, normal, etc.
                Comments

                Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

                Control0..*
                This element is affected by the following invariants: ele-1
                BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
                (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

                Codes identifying interpretations of observations.

                TypeCodeableConcept
                Requirements

                For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

                Alternate NamesAbnormal Flag
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                102. Observation.component.referenceRange
                Definition

                Guidance on how to interpret the value by comparison to a normal or recommended range.

                ShortProvides guide for interpretation of component result
                Comments

                Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this might not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

                Control0..*
                TypeSeettp://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange
                Requirements

                Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.