LinuxForHealth FHIR Implementation Guide
8.0.0 - draft United States of America flag

LinuxForHealth FHIR Implementation Guide - Local Development build (v8.0.0). See the Directory of published versions

Resource Profile: MeasurePopulationObservation - Detailed Descriptions

Active as of 2022-11-10

Definitions for the measure-population-observation resource profile.

1. Observation
2. Observation.extension
Control20..*
SlicingThis element introduces a set of slices on Observation.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
3. Observation.extension:canonicalMeasure
SliceNamecanonicalMeasure
Definition

Canonical reference to the specific version of the measure used to generate the population

Control1..1
TypeExtension(CanonicalMeasure) (Extension Type: canonical)
4. Observation.extension:measurePopulationId
SliceNamemeasurePopulationId
Definition

User-friendly textual key (internal use only) that identifies a specific population. This id should be unique across all measures and should not change when a measure is versioned or when overrides are applied. This value identifies the specific care gap or other population.

Control1..1
TypeExtension(MeasurePopulationId) (Extension Type: id)
5. Observation.extension:assignedPractitioner
SliceNameassignedPractitioner
Definition

The practitioners assigned to the patient when the measure population obserevation was identified

Control0..*
TypeExtension(AssignedPractitioner) (Extension Type: Reference(PractitionerPractitionerRole)))
6. Observation.extension:careGapComplianceMet
SliceNamecareGapComplianceMet
Definition

Indicates if the patient received the targeted treatment to close the care gap

Control0..1
TypeExtension(CareGapComplianceMet) (Extension Type: boolean)
7. Observation.extension:relatedObservation
SliceNamerelatedObservation
Definition

Related observations that can be combined to fulfill a single time period for a given care gap or other measure population

Control0..*
TypeExtension(RelatedObservation) (Extension Type: Reference(MeasurePopulationObservation)))
8. Observation.identifier:Derived
SliceNameDerived
NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
9. Observation.identifier:Derived.use
Control0..?
Pattern Valueofficial
10. Observation.identifier:Derived.type
Control1..?
Pattern Value<valueCodeableConcept xmlns="http://hl7.org/fhir">
  <coding>
    <system value="http://linuxforhealth.org/fhir/cdm/CodeSystem/identifier-type"/>
    <code value="DRI"/>
  </coding>
</valueCodeableConcept>
11. Observation.basedOn
Control0..0*
12. Observation.partOf
Control0..0*
13. Observation.category
Control0..0*
14. Observation.code
Definition

Type of observation (code / type), initial-population | numerator | numerator-exclusion | denominator | denominator-exclusion | denominator-exception | measure-population | measure-population-exclusion | measure-observation | care-gap

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

BindingThe codes SHALL be taken from Measure Population Type Value Set; other codes may be used where these codes are not suitableFor example codes, see LOINCCodes
15. Observation.subject
Control10..1
TypeReference(Patient|Group|Device|Location))
16. Observation.focus
Control0..0*
17. Observation.encounter
Control0..01
18. Observation.effective[x]
Control10..1
TypeChoice of: , dateTime, Timing, instant
[x] NoteSee Choice of Data Types for further information about how to use [x]
19. Observation.issued
Control0..01
20. Observation.performer
Control0..0*
21. Observation.value[x]
Control0..01
[x] NoteSee Choice of Data Types for further information about how to use [x]
22. Observation.dataAbsentReason
Control0..01
23. Observation.interpretation
Control0..0*
24. Observation.note
Control0..0*
25. Observation.bodySite
Control0..01
26. Observation.method
Control0..01
27. Observation.specimen
Control0..01
28. Observation.device
Control0..01
29. Observation.referenceRange
Control0..0*
30. Observation.hasMember
Control0..0*
31. Observation.component
Control0..0*
1. Observation
Definition

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

Control0..*
Alternate NamesVital Signs, Measurement, Results, Tests
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.

InvariantsDefined on this element
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())
obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (: dataAbsentReason.empty() or value.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())
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.

Control0..1
Typeuri
Is Modifiertrue
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. 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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
3. 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.

Control0..0*
TypeResource
Alternate Namesinline resources, anonymous resources, contained resources
Comments

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

4. Observation.extension
Definition

An Extension

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

Control20..*
TypeExtension
Alternate Namesextensions, user content
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Observation.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
5. Observation.extension:canonicalMeasure
SliceNamecanonicalMeasure
Definition

Canonical reference to the specific version of the measure used to generate the population

Control1..1 This element is affected by the following invariants: ele-1
TypeExtension(CanonicalMeasure) (Extension Type: canonical)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
6. Observation.extension:measurePopulationId
SliceNamemeasurePopulationId
Definition

User-friendly textual key (internal use only) that identifies a specific population. This id should be unique across all measures and should not change when a measure is versioned or when overrides are applied. This value identifies the specific care gap or other population.

Control1..1 This element is affected by the following invariants: ele-1
TypeExtension(MeasurePopulationId) (Extension Type: id)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
7. Observation.extension:assignedPractitioner
SliceNameassignedPractitioner
Definition

The practitioners assigned to the patient when the measure population obserevation was identified

Control0..* This element is affected by the following invariants: ele-1
TypeExtension(AssignedPractitioner) (Extension Type: Reference(PractitionerPractitionerRole)))
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
8. Observation.extension:careGapComplianceMet
SliceNamecareGapComplianceMet
Definition

Indicates if the patient received the targeted treatment to close the care gap

Control0..1 This element is affected by the following invariants: ele-1
TypeExtension(CareGapComplianceMet) (Extension Type: boolean)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
9. Observation.extension:relatedObservation
SliceNamerelatedObservation
Definition

Related observations that can be combined to fulfill a single time period for a given care gap or other measure population

Control0..* This element is affected by the following invariants: ele-1
TypeExtension(RelatedObservation) (Extension Type: Reference(MeasurePopulationObservation)))
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
10. 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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
11. Observation.identifier
Definition

A unique identifier assigned to this observation.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control10..*
TypeIdentifier
Requirements

Allows observations to be distinguished and referenced.

InvariantsDefined on this element
ele-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.identifier. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ type
12. Observation.identifier:Source
SliceNameSource
Definition

A unique identifier assigned to this observation.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1*
TypeIdentifier
Requirements

Allows observations to be distinguished and referenced.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
13. Observation.identifier:Source.use
Definition

The purpose of this identifier.

Control0..1
BindingThe codes SHALL be taken from IdentifierUse

Identifies the purpose for this identifier, if known .

Typecode
Is Modifiertrue
Requirements

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

Comments

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Pattern Valueofficial
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
14. Observation.identifier:Source.type
Definition

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

Control10..1
BindingThe codes SHALL be taken from Identifier Type Codes; other codes may be used where these codes are not suitable

A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

TypeCodeableConcept
Requirements

Allows users to make use of identifiers when the identifier system is not known.

Comments

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

Pattern Value<valueCodeableConcept xmlns="http://hl7.org/fhir">
  <coding>
    <system value="http://linuxforhealth.org/fhir/cdm/CodeSystem/identifier-type"/>
    <code value="SSRI"/>
  </coding>
</valueCodeableConcept>
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
15. Observation.identifier:Derived
SliceNameDerived
Definition

A unique identifier assigned to this observation.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1*
TypeIdentifier
Requirements

Allows observations to be distinguished and referenced.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
16. Observation.identifier:Derived.use
Definition

The purpose of this identifier.

Control0..1
BindingThe codes SHALL be taken from IdentifierUse

Identifies the purpose for this identifier, if known .

Typecode
Is Modifiertrue
Requirements

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

Comments

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Pattern Valueofficial
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
17. Observation.identifier:Derived.type
Definition

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

Control10..1
BindingThe codes SHALL be taken from Identifier Type Codes; other codes may be used where these codes are not suitable

A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

TypeCodeableConcept
Requirements

Allows users to make use of identifiers when the identifier system is not known.

Comments

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

Pattern Value<valueCodeableConcept xmlns="http://hl7.org/fhir">
  <coding>
    <system value="http://linuxforhealth.org/fhir/cdm/CodeSystem/identifier-type"/>
    <code value="DRI"/>
  </coding>
</valueCodeableConcept>
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
18. 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.

Control0..0*
TypeReference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|NutritionOrder|ServiceRequest))
Requirements

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

Alternate NamesFulfills
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
19. 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.

Control0..0*
TypeReference(MedicationAdministration|MedicationDispense|MedicationStatement|Procedure|Immunization|ImagingStudy))
Alternate NamesContainer
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
20. Observation.status
Definition

The status of the result value.

Control1..1
BindingThe codes SHALL be taken from ObservationStatus

Codes providing the status of an observation.

Typecode
Is Modifiertrue
Requirements

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

Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
21. Observation.category
Definition

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

Control0..0*
BindingThe codes SHOULD be taken from ObservationCategoryCodes

Codes for high level observation categories.

TypeCodeableConcept
Requirements

Used for filtering what observations are retrieved and displayed.

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
22. Observation.code
Definition

Type of observation (code / type), initial-population | numerator | numerator-exclusion | denominator | denominator-exclusion | denominator-exception | measure-population | measure-population-exclusion | measure-observation | care-gap

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

Control1..1
BindingThe codes SHALL be taken from Measure Population Type Value Set; other codes may be used where these codes are not suitableFor example codes, see LOINCCodes
TypeCodeableConcept
Requirements

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

Alternate NamesName
Comments

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
23. Observation.subject
Definition

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.

Control10..1
TypeReference(Patient|Group|Device|Location))
Requirements

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
24. 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.

Control0..0*
TypeReference(Resource))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
25. Observation.encounter
Definition

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

Control0..01
TypeReference(Encounter))
Requirements

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

Alternate NamesContext
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).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
26. Observation.effective[x]
Definition

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.

Control10..1
TypeChoice of: Period, dateTime, Timing, instant
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

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

Alternate NamesOccurrence
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
27. 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.

Control0..01
Typeinstant
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
28. Observation.performer
Definition

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

Control0..0*
TypeReference(Practitioner|PractitionerRole|Organization|CareTeam|Patient|RelatedPerson))
Requirements

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
29. Observation.value[x]
Definition

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

Control0..01 This element is affected by the following invariants: obs-7
TypeChoice of: Quantity(QuantityWithConversion), string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period, CodeableConcept
[x] NoteSee Choice of Data Types for further information about how to use [x]
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.

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
30. Observation.dataAbsentReason
Definition

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

Control0..01 This element is affected by the following invariants: obs-6
BindingThe codes SHALL be taken from DataAbsentReason; other codes may be used where these codes are not suitable

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

TypeCodeableConcept
Requirements

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

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
31. Observation.interpretation
Definition

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

Control0..0*
BindingThe codes SHALL be taken from ObservationInterpretationCodes; other codes may be used where these codes are not suitable

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
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
32. Observation.note
Definition

Comments about the observation or the results.

Control0..0*
TypeAnnotation
Requirements

Need to be able to provide free text additional information.

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
33. Observation.bodySite
Definition

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

Control0..01
BindingFor example codes, see SNOMEDCTBodyStructures

Codes describing anatomical locations. May include laterality.

TypeCodeableConcept
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
34. Observation.method
Definition

Indicates the mechanism used to perform the observation.

Control0..01
BindingFor example codes, see ObservationMethods

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.

Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
35. Observation.specimen
Definition

The specimen that was used when this observation was made.

Control0..01
TypeReference(Specimen))
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).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
36. Observation.device
Definition

The device used to generate the observation data.

Control0..01
TypeReference(Device|DeviceMetric))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
37. 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.

Control0..0*
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.

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.

InvariantsDefined on this element
ele-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())
38. 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.

Control0..0*
TypeReference(Observation|QuestionnaireResponse|MolecularSequence))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
39. 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.

Control0..0*
TypeBackboneElement
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.

Comments

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

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

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

Control0..*
Alternate NamesVital SignsMeasurementResultsTests
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.

2. Observation.id
Definition

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

Control0..1
Typeid
Comments

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

3. Observation.meta
Definition

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

Control0..1 This element is affected by the following invariants: ele-1
TypeMeta(ProcessMeta)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
4. 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.

Control0..1
Typeuri
Is Modifiertrue
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. 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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
5. Observation.language
Definition

The base language in which the resource is written.

Control0..1
BindingThe codes SHOULD be taken from CommonLanguages A human language
Additional BindingsPurpose
AllLanguagesMax Binding
Typecode
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
6. 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.

Control0..1
TypeNarrative
Alternate Namesnarrativehtmlxhtmldisplay
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
7. 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.

Control0..0
TypeResource
Alternate Namesinline resourcesanonymous resourcescontained 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.

8. Observation.extension
Definition

An Extension

Control2..*
TypeExtension
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Observation.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
9. Observation.extension:canonicalMeasure
SliceNamecanonicalMeasure
Definition

Canonical reference to the specific version of the measure used to generate the population

Control1..1 This element is affected by the following invariants: ele-1
TypeExtension(CanonicalMeasure) (Extension Type: canonical)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
10. Observation.extension:measurePopulationId
SliceNamemeasurePopulationId
Definition

User-friendly textual key (internal use only) that identifies a specific population. This id should be unique across all measures and should not change when a measure is versioned or when overrides are applied. This value identifies the specific care gap or other population.

Control1..1 This element is affected by the following invariants: ele-1
TypeExtension(MeasurePopulationId) (Extension Type: id)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
11. Observation.extension:assignedPractitioner
SliceNameassignedPractitioner
Definition

The practitioners assigned to the patient when the measure population obserevation was identified

Control0..* This element is affected by the following invariants: ele-1
TypeExtension(AssignedPractitioner) (Extension Type: Reference(PractitionerPractitionerRole)))
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
12. Observation.extension:careGapComplianceMet
SliceNamecareGapComplianceMet
Definition

Indicates if the patient received the targeted treatment to close the care gap

Control0..1 This element is affected by the following invariants: ele-1
TypeExtension(CareGapComplianceMet) (Extension Type: boolean)
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
13. Observation.extension:relatedObservation
SliceNamerelatedObservation
Definition

Related observations that can be combined to fulfill a single time period for a given care gap or other measure population

Control0..* This element is affected by the following invariants: ele-1
TypeExtension(RelatedObservation) (Extension Type: Reference(MeasurePopulationObservation)))
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
14. 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).

Control0..*
TypeExtension
Is Modifiertrue
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 Namesextensionsuser content
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
15. Observation.identifier
Definition

A unique identifier assigned to this observation.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control1..*
TypeIdentifier
Requirements

Allows observations to be distinguished and referenced.

InvariantsDefined on this element
ele-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.identifier. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ type
16. Observation.identifier:Source
SliceNameSource
Definition

A unique identifier assigned to this observation.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Requirements

Allows observations to be distinguished and referenced.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
17. Observation.identifier:Source.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
18. Observation.identifier:Source.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.

Control0..*
TypeExtension
Alternate Namesextensionsuser content
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Observation.identifier.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
19. Observation.identifier:Source.use
Definition

The purpose of this identifier.

Control0..1
BindingThe codes SHALL be taken from IdentifierUse Identifies the purpose for this identifier, if known
Typecode
Is Modifiertrue
Requirements

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

Comments

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Pattern Valueofficial
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
20. Observation.identifier:Source.type
Definition

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

Control1..1
BindingThe codes SHALL be taken from Identifier Type Codes; other codes may be used where these codes are not suitable A coded type for an identifier that can be used to determine which identifier to use for a specific purpose
TypeCodeableConcept
Requirements

Allows users to make use of identifiers when the identifier system is not known.

Comments

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

Pattern Value<valueCodeableConcept xmlns="http://hl7.org/fhir">
  <coding>
    <system value="http://linuxforhealth.org/fhir/cdm/CodeSystem/identifier-type"/>
    <code value="SSRI"/>
  </coding>
</valueCodeableConcept>
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
21. Observation.identifier:Source.system
Definition

Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

Control0..1
Typeuri
Requirements

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

Comments

Identifier.system is always case sensitive.

Example
General:http://www.acme.com/identifiers/patient
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
22. Observation.identifier:Source.value
Definition

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

Control0..1
Typestring
Comments

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

Example
General:123456
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
23. Observation.identifier:Source.period
Definition

Time period during which identifier is/was valid for use.

Control0..1
TypePeriod
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
24. Observation.identifier:Source.assigner
Definition

Organization that issued/manages the identifier.

Control0..1
TypeReference(Organization))
Comments

The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
25. Observation.identifier:Derived
SliceNameDerived
Definition

A unique identifier assigned to this observation.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Requirements

Allows observations to be distinguished and referenced.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
26. Observation.identifier:Derived.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
27. Observation.identifier:Derived.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.

Control0..*
TypeExtension
Alternate Namesextensionsuser content
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (: extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Observation.identifier.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
28. Observation.identifier:Derived.use
Definition

The purpose of this identifier.

Control0..1
BindingThe codes SHALL be taken from IdentifierUse Identifies the purpose for this identifier, if known
Typecode
Is Modifiertrue
Requirements

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

Comments

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Pattern Valueofficial
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
29. Observation.identifier:Derived.type
Definition

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

Control1..1
BindingThe codes SHALL be taken from Identifier Type Codes; other codes may be used where these codes are not suitable A coded type for an identifier that can be used to determine which identifier to use for a specific purpose
TypeCodeableConcept
Requirements

Allows users to make use of identifiers when the identifier system is not known.

Comments

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

Pattern Value<valueCodeableConcept xmlns="http://hl7.org/fhir">
  <coding>
    <system value="http://linuxforhealth.org/fhir/cdm/CodeSystem/identifier-type"/>
    <code value="DRI"/>
  </coding>
</valueCodeableConcept>
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
30. Observation.identifier:Derived.system
Definition

Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

Control0..1
Typeuri
Requirements

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

Comments

Identifier.system is always case sensitive.

Example
General:http://www.acme.com/identifiers/patient
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
31. Observation.identifier:Derived.value
Definition

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

Control0..1
Typestring
Comments

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

Example
General:123456
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
32. Observation.identifier:Derived.period
Definition

Time period during which identifier is/was valid for use.

Control0..1
TypePeriod
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
33. Observation.identifier:Derived.assigner
Definition

Organization that issued/manages the identifier.

Control0..1
TypeReference(Organization))
Comments

The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
34. 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.

Control0..0
TypeReference(CarePlanDeviceRequestImmunizationRecommendationMedicationRequestNutritionOrderServiceRequest))
Requirements

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

Alternate NamesFulfills
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
35. 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.

Control0..0
TypeReference(MedicationAdministrationMedicationDispenseMedicationStatementProcedureImmunizationImagingStudy))
Alternate NamesContainer
Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
36. Observation.status
Definition

The status of the result value.

Control1..1
BindingThe codes SHALL be taken from ObservationStatus Codes providing the status of an observation
Typecode
Is Modifiertrue
Requirements

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

Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
37. Observation.category
Definition

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

Control0..0
BindingThe codes SHOULD be taken from ObservationCategoryCodes Codes for high level observation categories
TypeCodeableConcept
Requirements

Used for filtering what observations are retrieved and displayed.

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
38. Observation.code
Definition

Type of observation (code / type), initial-population | numerator | numerator-exclusion | denominator | denominator-exclusion | denominator-exception | measure-population | measure-population-exclusion | measure-observation | care-gap

Control1..1
BindingThe codes SHALL be taken from Measure Population Type Value Set; other codes may be used where these codes are not suitable
TypeCodeableConcept
Requirements

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

Alternate NamesName
Comments

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
39. Observation.subject
Definition

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.

Control1..1
TypeReference(Patient))
Requirements

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
40. 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.

Control0..0
TypeReference(Resource))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
41. Observation.encounter
Definition

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

Control0..0
TypeReference(Encounter))
Requirements

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

Alternate NamesContext
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).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
42. Observation.effective[x]
Definition

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.

Control1..1
TypePeriod
[x] NoteSee Choice of Data Types for further information about how to use [x]
Requirements

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

Alternate NamesOccurrence
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
43. 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.

Control0..0
Typeinstant
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.

InvariantsDefined on this element
ele-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".

Control0..0
TypeReference(PractitionerPractitionerRoleOrganizationCareTeamPatientRelatedPerson))
Requirements

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
45. Observation.value[x]
Definition

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

Control0..0 This element is affected by the following invariants: obs-7
TypeChoice of: Quantity(QuantityWithConversion), string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
[x] NoteSee Choice of Data Types for further information about how to use [x]
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.

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
46. Observation.dataAbsentReason
Definition

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

Control0..0 This element is affected by the following invariants: obs-6
BindingThe codes SHALL be taken from DataAbsentReason; other codes may be used where these codes are not suitable Codes specifying why the result (Observation.value[x]) is missing
TypeCodeableConcept
Requirements

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

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
47. Observation.interpretation
Definition

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

Control0..0
BindingThe codes SHALL be taken from ObservationInterpretationCodes; other codes may be used where these codes are not suitable 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
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
48. Observation.note
Definition

Comments about the observation or the results.

Control0..0
TypeAnnotation
Requirements

Need to be able to provide free text additional information.

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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
49. Observation.bodySite
Definition

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

Control0..0
BindingFor example codes, see SNOMEDCTBodyStructures Codes describing anatomical locations. May include laterality
TypeCodeableConcept
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
50. Observation.method
Definition

Indicates the mechanism used to perform the observation.

Control0..0
BindingFor example codes, see ObservationMethods 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.

Comments

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
51. Observation.specimen
Definition

The specimen that was used when this observation was made.

Control0..0
TypeReference(Specimen))
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).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
52. Observation.device
Definition

The device used to generate the observation data.

Control0..0
TypeReference(DeviceDeviceMetric))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
53. 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.

Control0..0
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.

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.

InvariantsDefined on this element
ele-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())
54. 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.

Control0..0
TypeReference(ObservationQuestionnaireResponseMolecularSequence))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
55. 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.

Control0..*
TypeReference(DocumentReferenceImagingStudyMediaQuestionnaireResponseObservationMolecularSequence))
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
56. 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.

Control0..0
TypeBackboneElement
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.

Comments

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

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