R4 Ballot #1 (Mixed Normative/Trial use) Current Build
This is the FHIR R4 Mixed Normative/Trial Use Ballot #1, and the version for the Cologne Connectathon in May 2018. The current version is R3 . See the ballot introduction for details about the ballot. For a full list of available versions, see the Directory of published versions and Timelines for an explanation of STU and other statuses.

10.1 Resource Observation - Content

Orders and Observations Work Group Maturity Level : 5 N   Normative (from v4.0.0) Security Category : Patient Compartments : Device , Encounter , Patient , Practitioner , RelatedPerson
Normative Candidate Note: This page is candidate normative content for R4 in the Observation Package . Once normative, it will lose it's Maturity Level, and breaking changes will no longer be made.

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

Note to balloters The Orders and Observations work-group wants to draw the attention of reviewers and implementers to the following significant changes to this resource: The guidance on using code value pairs to represent observations in FHIR Breaking Change The replacement of the .related complex element with direct inline elements based on the types listed in ObservationRelationshipType : .derivedFrom and .hasMember This change allows for more flexibility in adding additional reference targets as well as a simplifying the structure. The other relationship types were considered to be outside the 80% and only sequel-to and replaces were made into standard extensions referencing a target Observation. Breaking Change The removal of the Attachment data type as a choice for .value[x] . As a result of 2, direct links to Media were added. Observations that require the attachment data types are represented by the Media resource. This change eliminates the ambiguity and duplication on how to represent multimedia observations. Substantive Change The promotion of the event-partOf extension to an inline element . This allows a direct reference to an event in which the observation was made (for example a procedure). Substantive Change The promotion and expansion of the focal-subject extension to an inline element . This allows a direct reference to a resource if the actual focus of an observation when it is not the patient of record. A simple example is provided here . Note that there is still the focus-code extension for when the focus is a code. The Scope and Boundaries section below has been rewritten to acknowledge the potential for Observation to be used instead of other resource and provide some overarching guidance on when other resources are more appropriate. Review of the standard event extensions which are the result of alignment with the workflow Event pattern

This resource is an event resource from a FHIR workflow perspective - see Workflow .

Observations are a central element in healthcare, used to support diagnosis, monitor progress, determine baselines and patterns and even capture demographic characteristics. Most observations are simple name/value pair assertions with some metadata, but some observations group other observations together logically, or even are multi-component observations. Note that the DiagnosticReport resource provides a clinical or workflow context for a set of observations and the Observation resource is referenced by DiagnosticReport to represent laboratory, imaging, and other clinical and diagnostic data to form a complete report.

Uses for the Observation resource include:

* The boundaries between clinical findings and disorders remains a challenge in medical ontology. Refer the Boundaries section below and in Condition for general guidance. These boundaries can be clarified by profiling Observation for a particular use case.

The following core profiles for the Observation resource have been defined as well. If implementations use this Resource when expressing the profile-specific concepts as structured data, they SHALL conform to the following profiles:

Profile Description
Vital signs The FHIR Vital Signs profile sets minimum expectations for the Observation Resource to record, search and fetch the vital signs (e.g. temperature, blood pressure, respiration rate, etc.) associated with a patient

At its core, Observation allows expressing a name-value pair or structured collection of name-value pairs. As such, it can support conveying any type of information desired. However, that is not its intent. Observation is intended for capturing measurements and subjective point-in-time assessments. It is not intended to be used for those specific contexts and use cases already covered by other FHIR resources. For example, the AllergyIntolerance resource represents a patient allergies, MedicationStatement resource: medications taken by a patient, FamilyMemberHistory resource: a patient's family history, Procedure resource: information about a procedure, and QuestionnaireResponse resource: a set of answers to a set of questions. The Observation resource should not be used to record clinical diagnosis about a patient or subject that are typically captured in the Condition resource or the ClinicalImpression resource. The Observation resource is often referenced by the Condition resource to provide specific subjective and objective data to support its assertions. There will however be situations of overlap. For example, a response to a question of "have you ever taken illicit drugs" could in principle be represented using MedicationStatement, but most systems would treat such an assertion as an Observation. In some cases, such as when source data is coming from an HL7 v2 feed, a system might not have information that allows it to distinguish diagnosis, allergy and other "specialized" types of observations from laboratory, vital sign and other observation types intended to be conveyed with this resource. In those circumstances, such specialized observations may also appear using this resource. Adhering to such convention is an appropriate use of Observation. If implementers are uncertain whether a proposed use of Observation is appropriate, they're encouraged to consult with implementers on chat.fhir.org implementer's stream

The Media resource captures a specific type of observation whose value is audio, video or image data. This resource is used instead of Observation to represent such forms of information as it exposes the metadata relevant for interpreting the information. See Media's boundaries section to see how Media (and Observation) differs from ImagingStudy and DocumentReference .

In contrast to the Observation resource, the DiagnosticReport resource typically includes additional clinical context and some mix of atomic results, images, imaging reports, textual and coded interpretation, and formatted representations. Laboratory reports, pathology reports, and imaging reports should be represented using the DiagnosticReport resource. The Observation resource is referenced by the DiagnosticReport to provide the atomic results for a particular investigation. "Laboratories routinely have a variable that is summative across a series of discrete variables - these are usually called 'impressions' or 'interpretations'. Sometimes they are algorithmically specified and sometimes they have the imprimatur of pathologists and they are conveyed in Observation or DiagnosticReport instead of the Clinical Impression resource. The Observation resource should not be used to record clinical diagnosis about a patient or subject as discussed above.

This resource is referenced by AdverseEvent , Appointment , CarePlan , ChargeItem , ClinicalImpression , Communication , CommunicationRequest , Condition , Contract , DeviceRequest , DeviceUseStatement , DiagnosticReport , Encounter , FamilyMemberHistory , Goal , GuidanceResponse , ImagingStudy , Immunization , MedicationAdministration , MedicationRequest , MedicationStatement , MolecularSequence , itself, Procedure , QuestionnaireResponse , RequestGroup , RiskAssessment , Sequence , ServiceRequest and SupplyRequest

Structure

Name Flags Card. Type Description & Constraints doco
. . Observation I N DomainResource Measurements and simple assertions
+ Rule: dataAbsentReason SHALL only be present if Observation.value[x] is not present
+ Rule: If Observation.code is the same as a an Observation.component.code then the value element associated with the code SHALL NOT be present
+ dataAbsentReason SHALL only be present if Observation.value[x] is not present Elements defined in Ancestors: id , meta , implicitRules , language , text , contained , extension , modifierExtension
. . . identifier Σ 0..* Identifier Business Identifier for observation
. . . basedOn Σ 0..* Reference ( CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest ) Fulfills plan, proposal or order
. . . partOf Σ 0..* Reference ( MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy ) Part of referenced event
. . . status ?! Σ 1..1 code registered | preliminary | final | amended +
ObservationStatus ( Required )
. . . category 0..* CodeableConcept Classification of type of observation
Observation Category Codes ( Preferred )
. . . code Σ 1..1 CodeableConcept Type of observation (code / type)
LOINC Codes ( Example )
. . . subject Σ 0..1 Reference ( Patient | Group | Device | Location ) Who and/or what this the observation is about
. . . focus Σ TU 0..1 0..* Reference ( Any ) The "focal point" of What the observation is about, when it is not about the subject of record
. . . context encounter Σ 0..1 Reference ( Encounter | EpisodeOfCare ) Healthcare event during which this observation is made
. . . effective[x] Σ 0..1 Clinically relevant time/time-period for observation
. . . . effectiveDateTime dateTime
. . . . effectivePeriod Period
. . . . effectiveTiming Timing
. . . . effectiveInstant instant
. . . issued Σ 0..1 instant Date/Time this version was made available
. . . performer Σ 0..* Reference ( Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson ) Who is responsible for the observation
. . . value[x] Σ I 0..1 Actual result
. . . . valueQuantity Quantity
. . . . valueCodeableConcept CodeableConcept
. . . . valueString string
. . . . valueBoolean boolean
. . . . valueInteger integer
. . . . valueRange Range
. . . . valueRatio Ratio
. . . . valueSampledData SampledData
. . . . valueTime time
. . . . valueDateTime dateTime
. . . . valuePeriod Period
. . . dataAbsentReason I 0..1 CodeableConcept Why the result is missing
DataAbsentReason ( Extensible )
. . . interpretation 0..1 0..* CodeableConcept High, low, normal, etc.
Observation Interpretation Codes ( Extensible )
. . comment . note 0..1 0..* string Annotation Comments about result the observation
. . . bodySite 0..1 CodeableConcept Observed body part
SNOMED CT Body Structures ( Example )
. . . method 0..1 CodeableConcept How it was done
Observation Methods ( Example )
. . . specimen 0..1 Reference ( Specimen ) Specimen used for this observation
. . . device 0..1 Reference ( Device | DeviceComponent | DeviceMetric ) (Measurement) Device
. . . referenceRange I 0..* BackboneElement Provides guide for interpretation
+ Rule: Must have at least a low or a high or text
. . . . low I 0..1 SimpleQuantity Low Range, if relevant
. . . . high I 0..1 SimpleQuantity High Range, if relevant
. . . . type 0..1 CodeableConcept Reference range qualifier
Observation Reference Range Meaning Codes ( Extensible Preferred )
. . . . appliesTo 0..* CodeableConcept Reference range population
Observation Reference Range Applies To Codes ( Example )
. . . . age 0..1 Range Applicable age range, if relevant
. . . . text 0..1 string Text based reference range in an observation
. . . hasMember Σ 0..* Reference ( Observation | QuestionnaireResponse | Sequence MolecularSequence ) Related resource that belongs to the Observation group
. . . derivedFrom Σ 0..* Reference ( DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | Sequence MolecularSequence ) Related measurements the observation is made from
. . . component Σ 0..* BackboneElement Component results
. . . . code Σ 1..1 CodeableConcept Type of component observation (code / type)
LOINC Codes ( Example )
. . . . value[x] Σ 0..1 Actual component result
. . . . . valueQuantity Quantity
. . . . . valueCodeableConcept CodeableConcept
. . . . . valueString string
. . . . . valueBoolean boolean
. . . . . valueInteger integer
. . . . . valueRange Range
. . . . . valueRatio Ratio
. . . . . valueSampledData SampledData
. . . . . valueTime time
. . . . . valueDateTime dateTime
. . . . . valuePeriod Period
. . . . dataAbsentReason I 0..1 CodeableConcept Why the component result is missing
DataAbsentReason ( Extensible )
. . . . interpretation 0..1 0..* CodeableConcept High, low, normal, etc.
Observation Interpretation Codes ( Extensible )
. . . . referenceRange 0..* see referenceRange Provides guide for interpretation of component result

doco Documentation for this format

UML Diagram ( Legend )

Observation ( DomainResource ) A unique identifier assigned to this observation identifier : Identifier [0..*] A plan, proposal or order that is fulfilled in whole or in part by this event event. For example, a MedicationRequest may require a patient to have laboratory test performed before it is dispensed basedOn : Reference [0..*] « CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest » A larger event of which this particular Observation is a component or step. For example, an observation as part of a procedure partOf : Reference [0..*] « MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy » The status of the result value (this element modifies the meaning of other elements) status : code [1..1] « Codes providing the status of an observation. (Strength=Required) ObservationStatus ! » A code that classifies the general type of observation being made category : CodeableConcept [0..*] « Codes for high level observation categories. (Strength=Preferred) Observation Category ObservationCategoryCodes ? » Describes what was observed. Sometimes this is called the observation "name" code : CodeableConcept [1..1] « Codes identifying names of simple observations. (Strength=Example) LOINC LOINCCodes ?? » The patient, or group of patients, location, or device whose characteristics (direct or indirect) are described by the this observation is about and into whose record the observation is placed. Comments: Indirect characteristics may be those If the actual focus of the observation is different from the subject (or a specimen, fetus, donor, other observer (for example a relative sample of, part, or EMT), region of the subject), the `focus` element or any observation made about the subject `code` itself specifies the actual focus of the observation subject : Reference [0..1] « Patient | Group | Device | Location » The actual focus of an observation when it is not the patient of record. The focus is point of attention when the observation record representing something or someone associated with the patient. It could be patient such as a spouse or spouse, parent, a fetus 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 focus : Reference [0..1] [0..*] « Any » The healthcare event (e.g. a patient and healthcare provider interaction) during which this observation is made context encounter : Reference [0..1] « Encounter | EpisodeOfCare » 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 effective[x] : Type [0..1] « dateTime | Period | Timing | instant » The date and time this version of the observation was made available to providers, typically after the results have been reviewed and verified issued : instant [0..1] Who was responsible for asserting the observed value as "true" performer : Reference [0..*] « Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson » The information determined as a result of making the observation, if the information has a simple value value[x] : Type [0..1] « Quantity | CodeableConcept | string | boolean | integer | Range | Ratio | SampledData | time | dateTime | Period » Provides a reason why the expected value in the element Observation.value[x] is missing dataAbsentReason : CodeableConcept [0..1] « Codes specifying why the result (`Observation.value[x]`) is missing. (Strength=Extensible) DataAbsentReason + » The A categorical assessment made based on the result of the observation. Intended as a simple compact code often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result. Otherwise known as abnormal flag an observation value. For example, high, low, normal interpretation : CodeableConcept [0..1] [0..*] « Codes identifying interpretations of observations. (Strength=Extensible) Observation Interpretation ObservationInterpretationCodes + » May include statements about significant, unexpected or unreliable values, or information Comments about the source of the value where this may be relevant to the interpretation of observation or the result results comment note : string Annotation [0..1] [0..*] Indicates the site on the subject's body where the observation was made (i.e. the target site) bodySite : CodeableConcept [0..1] « Codes describing anatomical locations. May include laterality. (Strength=Example) SNOMED CT Body Structures SNOMEDCTBodyStructures ?? » Indicates the mechanism used to perform the observation method : CodeableConcept [0..1] « Methods for simple observations. (Strength=Example) Observation Methods ObservationMethods ?? » The specimen that was used when this observation was made specimen : Reference [0..1] « Specimen » The device used to generate the observation data device : Reference [0..1] « Device | DeviceComponent | DeviceMetric » 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 hasMember : Reference [0..*] « Observation | QuestionnaireResponse | Sequence MolecularSequence » 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 derivedFrom : Reference [0..*] « DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | Sequence MolecularSequence » ReferenceRange 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) low : Quantity ( SimpleQuantity ) [0..1] 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) high : Quantity ( SimpleQuantity ) [0..1] Codes to indicate the what part of the targeted reference population it applies to. For example, the normal or therapeutic range type : CodeableConcept [0..1] « Code for the meaning of a reference range. (Strength=Extensible) (Strength=Preferred) Observation Reference Range M... ObservationReferenceRangeMean... + ? » 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 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 appliesTo : CodeableConcept [0..*] « Codes identifying the population the reference range applies to. (Strength=Example) Observation Reference Range A... ObservationReferenceRangeAppl... ?? » 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 age : Range [0..1] 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" text : string [0..1] Component Describes what was observed. Sometimes this is called the observation "code" code : CodeableConcept [1..1] « Codes identifying names of simple observations. (Strength=Example) LOINC LOINCCodes ?? » The information determined as a result of making the observation, if the information has a simple value value[x] : Type [0..1] « Quantity | CodeableConcept | string | boolean | integer | Range | Ratio | SampledData | time | dateTime | Period » Provides a reason why the expected value in the element Observation.component.value[x] is missing dataAbsentReason : CodeableConcept [0..1] « Codes specifying why the result (`Observation.value[x]`) is missing. (Strength=Extensible) DataAbsentReason + » The A categorical assessment made based on the result of the observation. Intended as a simple compact code often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result. Otherwise known as abnormal flag an observation value. For example, high, low, normal interpretation : CodeableConcept [0..1] [0..*] « Codes identifying interpretations of observations. (Strength=Extensible) Observation Interpretation ObservationInterpretationCodes + » Guidance on how to interpret the value by comparison to a normal or recommended range range. Multiple reference ranges are interpreted as an "OR". In other words, to represent two distinct target populations, two `referenceRange` elements would be used referenceRange [0..*] Guidance on how to interpret the value by comparison to a normal or recommended range referenceRange [0..*] 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 component [0..*]

XML Template

<Observation xmlns="http://hl7.org/fhir"> doco
 <!-- from Resource: id, meta, implicitRules, and language -->
 <!-- from DomainResource: text, contained, extension, and modifierExtension -->
 <identifier><!-- 0..* Identifier Business Identifier for observation --></identifier>
 <|

 <basedOn><!-- 0..* Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|

   MedicationRequest|NutritionOrder|ServiceRequest) Fulfills plan, proposal or order --></basedOn>
 <partOf><!-- 0..* Reference(MedicationAdministration|MedicationDispense|
   MedicationStatement|Procedure|Immunization|ImagingStudy) Part of referenced event --></partOf>
 <status value="[code]"/><!-- 1..1 registered | preliminary | final | amended + -->
 <category><!-- 0..* CodeableConcept Classification of  type of observation --></category>
 <code><!-- 1..1 CodeableConcept Type of observation (code / type) --></code>
 <</subject>
 <</focus>
 <</context>
 <</effective[x]>

 <subject><!-- 0..1 Reference(Patient|Group|Device|Location) Who and/or what the observation is about --></subject>
 <focus><!-- 0..* Reference(Any) What the observation is about, when it is not about the subject of record --></focus>
 <encounter><!-- 0..1 Reference(Encounter) Healthcare event during which this observation is made --></encounter>
 <effective[x]><!-- 0..1 dateTime|Period|Timing|instant Clinically relevant time/time-period for observation --></effective[x]>

 <issued value="[instant]"/><!-- 0..1 Date/Time this version was made available -->
 <performer><!-- 0..* Reference(Practitioner|PractitionerRole|Organization|
   CareTeam|Patient|RelatedPerson) Who is responsible for the observation --></performer>
 <|

 <value[x]><!-- ?? 0..1 Quantity|CodeableConcept|string|boolean|integer|Range|Ratio|

   SampledData|time|dateTime|Period Actual result --></value[x]>
 <dataAbsentReason><!-- ?? 0..1 CodeableConcept Why the result is missing --></dataAbsentReason>
 <</interpretation>
 <

 <interpretation><!-- 0..* CodeableConcept High, low, normal, etc. --></interpretation>
 <note><!-- 0..* Annotation Comments about the observation --></note>

 <bodySite><!-- 0..1 CodeableConcept Observed body part --></bodySite>
 <method><!-- 0..1 CodeableConcept How it was done --></method>
 <specimen><!-- 0..1 Reference(Specimen) Specimen used for this observation --></specimen>
 <</device>
 <

 <device><!-- 0..1 Reference(Device|DeviceMetric) (Measurement) Device --></device>
 <referenceRange>  <!-- 0..* Provides guide for interpretation -->

  <low><!-- ?? 0..1 Quantity(SimpleQuantity) Low Range, if relevant --></low>
  <high><!-- ?? 0..1 Quantity(SimpleQuantity) High Range, if relevant --></high>
  <type><!-- 0..1 CodeableConcept Reference range qualifier --></type>
  <</appliesTo>

  <appliesTo><!-- 0..* CodeableConcept Reference range population --></appliesTo>

  <age><!-- 0..1 Range Applicable age range, if relevant --></age>
  <text value="[string]"/><!-- 0..1 Text based reference range in an observation -->
 </referenceRange>
 <</hasMember>

 <hasMember><!-- 0..* Reference(Observation|QuestionnaireResponse|
   MolecularSequence) Related resource that belongs to the Observation group --></hasMember>
 <derivedFrom><!-- 0..* Reference(DocumentReference|ImagingStudy|Media|
   </derivedFrom>

   QuestionnaireResponse|Observation|MolecularSequence) Related measurements the observation is made from --></derivedFrom>
 <component>  <!-- 0..* Component results -->
  <code><!-- 1..1 CodeableConcept Type of component observation (code / type) --></code>
  <value[x]><!-- 0..1 Quantity|CodeableConcept|string|boolean|integer|Range|
    Ratio|SampledData|time|dateTime|Period Actual component result --></value[x]>
  <dataAbsentReason><!-- ?? 0..1 CodeableConcept Why the component result is missing --></dataAbsentReason>
  <</interpretation>

  <interpretation><!-- 0..* CodeableConcept High, low, normal, etc. --></interpretation>

  <referenceRange><!-- 0..* Content as for Observation.referenceRange Provides guide for interpretation of component result --></referenceRange>
 </component>
</Observation>

JSON Template

{doco
  "resourceType" : "Observation",
  // from Resource: id, meta, implicitRules, and language
  // from DomainResource: text, contained, extension, and modifierExtension
  "identifier" : [{ Identifier }], // Business Identifier for observation
  "|

  "basedOn" : [{ Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|

   MedicationRequest|NutritionOrder|ServiceRequest) }], // Fulfills plan, proposal or order
  "partOf" : [{ Reference(MedicationAdministration|MedicationDispense|
   MedicationStatement|Procedure|Immunization|ImagingStudy) }], // Part of referenced event
  "status" : "<code>", // R!  registered | preliminary | final | amended +
  "category" : [{ CodeableConcept }], // Classification of  type of observation
  "code" : { CodeableConcept }, // R!  Type of observation (code / type)
  "
  "
  "
  

  "subject" : { Reference(Patient|Group|Device|Location) }, // Who and/or what the observation is about
  "focus" : [{ Reference(Any) }], // What the observation is about, when it is not about the subject of record
  "encounter" : { Reference(Encounter) }, // Healthcare event during which this observation is made
  // effective[x]: Clinically relevant time/time-period for observation. One of these 4:
  "effectiveDateTime" : "<dateTime>",
  "effectivePeriod" : { Period },
  "effectiveTiming" : { Timing },
  "effectiveInstant" : "<instant>",

  "issued" : "<instant>", // Date/Time this version was made available
  "performer" : [{ Reference(Practitioner|PractitionerRole|Organization|
   CareTeam|Patient|RelatedPerson) }], // Who is responsible for the observation
  // value[x]: Actual result. One of these 11:
  "valueQuantity" : { Quantity },
  "valueCodeableConcept" : { CodeableConcept },
  "valueString" : "<string>",
  "valueBoolean" : <boolean>,
  "valueInteger" : <integer>,
  "valueRange" : { Range },
  "valueRatio" : { Ratio },
  "valueSampledData" : { SampledData },
  "valueTime" : "<time>",
  "valueDateTime" : "<dateTime>",
  "valuePeriod" : { Period },
  "dataAbsentReason" : { CodeableConcept }, // C? Why the result is missing
  "
  "

  "interpretation" : [{ CodeableConcept }], // High, low, normal, etc.
  "note" : [{ Annotation }], // Comments about the observation

  "bodySite" : { CodeableConcept }, // Observed body part
  "method" : { CodeableConcept }, // How it was done
  "specimen" : { Reference(Specimen) }, // Specimen used for this observation
  "
  "

  "device" : { Reference(Device|DeviceMetric) }, // (Measurement) Device
  "referenceRange" : [{ // Provides guide for interpretation

    "low" : { Quantity(SimpleQuantity) }, // C? Low Range, if relevant
    "high" : { Quantity(SimpleQuantity) }, // C? High Range, if relevant
    "type" : { CodeableConcept }, // Reference range qualifier
    "

    "appliesTo" : [{ CodeableConcept }], // Reference range population

    "age" : { Range }, // Applicable age range, if relevant
    "text" : "<string>" // Text based reference range in an observation
  }],
  "

  "hasMember" : [{ Reference(Observation|QuestionnaireResponse|
   MolecularSequence) }], // Related resource that belongs to the Observation group
  "derivedFrom" : [{ Reference(DocumentReference|ImagingStudy|Media|
   

   QuestionnaireResponse|Observation|MolecularSequence) }], // Related measurements the observation is made from
  "component" : [{ // Component results
    "code" : { CodeableConcept }, // R!  Type of component observation (code / type)
    // value[x]: Actual component result. One of these 11:
    "valueQuantity" : { Quantity },
    "valueCodeableConcept" : { CodeableConcept },
    "valueString" : "<string>",
    "valueBoolean" : <boolean>,
    "valueInteger" : <integer>,
    "valueRange" : { Range },
    "valueRatio" : { Ratio },
    "valueSampledData" : { SampledData },
    "valueTime" : "<time>",
    "valueDateTime" : "<dateTime>",
    "valuePeriod" : { Period },
    "dataAbsentReason" : { CodeableConcept }, // C? Why the component result is missing
    "

    "interpretation" : [{ CodeableConcept }], // High, low, normal, etc.

    "referenceRange" : [{ Content as for Observation.referenceRange }] // Provides guide for interpretation of component result
  }]
}

Turtle Template

@prefix fhir: <http://hl7.org/fhir/> .doco
[ a fhir:Observation;
  fhir:nodeRole fhir:treeRoot; # if this is the parser root
  # from Resource: .id, .meta, .implicitRules, and .language
  # from DomainResource: .text, .contained, .extension, and .modifierExtension
  fhir:Observation.identifier [ Identifier ], ... ; # 0..* Business Identifier for observation
  fhir:|

  fhir:Observation.basedOn [ Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|

  NutritionOrder|ServiceRequest) ], ... ; # 0..* Fulfills plan, proposal or order
  fhir:Observation.partOf [ Reference(MedicationAdministration|MedicationDispense|MedicationStatement|Procedure|
  Immunization|ImagingStudy) ], ... ; # 0..* Part of referenced event
  fhir:Observation.status [ code ]; # 1..1 registered | preliminary | final | amended +
  fhir:Observation.category [ CodeableConcept ], ... ; # 0..* Classification of  type of observation
  fhir:Observation.code [ CodeableConcept ]; # 1..1 Type of observation (code / type)
  fhir:
  fhir:
  fhir:
  # . One of these 3

  fhir:Observation.subject [ Reference(Patient|Group|Device|Location) ]; # 0..1 Who and/or what the observation is about
  fhir:Observation.focus [ Reference(Any) ], ... ; # 0..* What the observation is about, when it is not about the subject of record
  fhir:Observation.encounter [ Reference(Encounter) ]; # 0..1 Healthcare event during which this observation is made
  # Observation.effective[x] : 0..1 Clinically relevant time/time-period for observation. One of these 4

    fhir:Observation.effectiveDateTime [ dateTime ]
    fhir:Observation.effectivePeriod [ Period ]
    fhir:Observation.effectiveTiming [ Timing ]
    fhir:Observation.effectiveInstant [ instant ]

  fhir:Observation.issued [ instant ]; # 0..1 Date/Time this version was made available
  fhir:Observation.performer [ Reference(Practitioner|PractitionerRole|Organization|CareTeam|Patient|RelatedPerson) ], ... ; # 0..* Who is responsible for the observation
  # Observation.value[x] : 0..1 Actual result. One of these 11
    fhir:Observation.valueQuantity [ Quantity ]
    fhir:Observation.valueCodeableConcept [ CodeableConcept ]
    fhir:Observation.valueString [ string ]
    fhir:Observation.valueBoolean [ boolean ]
    fhir:Observation.valueInteger [ integer ]
    fhir:Observation.valueRange [ Range ]
    fhir:Observation.valueRatio [ Ratio ]
    fhir:Observation.valueSampledData [ SampledData ]
    fhir:Observation.valueTime [ time ]
    fhir:Observation.valueDateTime [ dateTime ]
    fhir:Observation.valuePeriod [ Period ]
  fhir:Observation.dataAbsentReason [ CodeableConcept ]; # 0..1 Why the result is missing
  fhir:
  fhir:

  fhir:Observation.interpretation [ CodeableConcept ], ... ; # 0..* High, low, normal, etc.
  fhir:Observation.note [ Annotation ], ... ; # 0..* Comments about the observation

  fhir:Observation.bodySite [ CodeableConcept ]; # 0..1 Observed body part
  fhir:Observation.method [ CodeableConcept ]; # 0..1 How it was done
  fhir:Observation.specimen [ Reference(Specimen) ]; # 0..1 Specimen used for this observation
  fhir:
  fhir:

  fhir:Observation.device [ Reference(Device|DeviceMetric) ]; # 0..1 (Measurement) Device
  fhir:Observation.referenceRange [ # 0..* Provides guide for interpretation

    fhir:Observation.referenceRange.low [ Quantity(SimpleQuantity) ]; # 0..1 Low Range, if relevant
    fhir:Observation.referenceRange.high [ Quantity(SimpleQuantity) ]; # 0..1 High Range, if relevant
    fhir:Observation.referenceRange.type [ CodeableConcept ]; # 0..1 Reference range qualifier
    fhir:

    fhir:Observation.referenceRange.appliesTo [ CodeableConcept ], ... ; # 0..* Reference range population

    fhir:Observation.referenceRange.age [ Range ]; # 0..1 Applicable age range, if relevant
    fhir:Observation.referenceRange.text [ string ]; # 0..1 Text based reference range in an observation
  ], ...;
  fhir:
  fhir:

  fhir:Observation.hasMember [ Reference(Observation|QuestionnaireResponse|MolecularSequence) ], ... ; # 0..* Related resource that belongs to the Observation group
  fhir:Observation.derivedFrom [ Reference(DocumentReference|ImagingStudy|Media|QuestionnaireResponse|Observation|
  MolecularSequence) ], ... ; # 0..* Related measurements the observation is made from
  fhir:Observation.component [ # 0..* Component results
    fhir:Observation.component.code [ CodeableConcept ]; # 1..1 Type of component observation (code / type)
    # Observation.component.value[x] : 0..1 Actual component result. One of these 11
      fhir:Observation.component.valueQuantity [ Quantity ]
      fhir:Observation.component.valueCodeableConcept [ CodeableConcept ]
      fhir:Observation.component.valueString [ string ]
      fhir:Observation.component.valueBoolean [ boolean ]
      fhir:Observation.component.valueInteger [ integer ]
      fhir:Observation.component.valueRange [ Range ]
      fhir:Observation.component.valueRatio [ Ratio ]
      fhir:Observation.component.valueSampledData [ SampledData ]
      fhir:Observation.component.valueTime [ time ]
      fhir:Observation.component.valueDateTime [ dateTime ]
      fhir:Observation.component.valuePeriod [ Period ]
    fhir:Observation.component.dataAbsentReason [ CodeableConcept ]; # 0..1 Why the component result is missing
    fhir:

    fhir:Observation.component.interpretation [ CodeableConcept ], ... ; # 0..* High, low, normal, etc.

    fhir:Observation.component.referenceRange [ See Observation.referenceRange ], ... ; # 0..* Provides guide for interpretation of component result
  ], ...;
]

Changes since R3

Observation
Observation.basedOn
  • Type changed from Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|NutritionOrder|ProcedureRequest|ReferralRequest) to Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|NutritionOrder|ServiceRequest) Reference: Added Target Type ServiceRequest
  • Type Reference: Removed Target Types ProcedureRequest, ReferralRequest
Observation.partOf
  • Added Element
Observation.status
  • Change value set from http://hl7.org/fhir/ValueSet/observation-status to http://hl7.org/fhir/ValueSet/observation-status|4.0.0
Observation.focus
  • Added Element
Observation.encounter
  • Renamed from context to encounter
  • Type Reference: Removed Target Type EpisodeOfCare
Observation.effective[x]
  • Add Timing Types Timing, instant
Observation.performer
  • Type changed from Reference(Practitioner|Organization|Patient|RelatedPerson) to Reference(Practitioner|PractitionerRole|Organization|CareTeam|Patient|RelatedPerson) Reference: Added Target Types PractitionerRole, CareTeam
Observation.value[x]
  • Remove Attachment, Add Type integer
  • Remove Type Attachment
Observation.dataAbsentReason
  • Change value set from http://hl7.org/fhir/ValueSet/observation-valueabsentreason to http://hl7.org/fhir/ValueSet/data-absent-reason
  • Change code system for extensibly bound codes from "http://hl7.org/fhir/data-absent-reason" to "http://terminology.hl7.org/CodeSystem/data-absent-reason"
Observation.device Observation.interpretation
  • Max Cardinality changed from 1 to *
  • Change code system for extensibly bound codes from "http://terminology.hl7.org/CodeSystem/v2-0078" to "http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"
Observation.note
  • Renamed from comment to note
  • Max Cardinality changed from 1 to *
  • Type changed from Reference(Device|DeviceMetric) string to Reference(Device|DeviceComponent|DeviceMetric) Annotation
Observation.referenceRange.type
  • Remove Binding http://hl7.org/fhir/ValueSet/referencerange-meaning (extensible)
Observation.hasMember
  • Added Element
Observation.derivedFrom
  • Added Element
Observation.component.value[x]
  • Remove Attachment, Add Types boolean, Add integer
  • Remove Type Attachment
Observation.component.dataAbsentReason
  • Change value set from http://hl7.org/fhir/ValueSet/observation-valueabsentreason to http://hl7.org/fhir/ValueSet/data-absent-reason
  • Change code system for extensibly bound codes from "http://hl7.org/fhir/data-absent-reason" to "http://terminology.hl7.org/CodeSystem/data-absent-reason"
Observation.component.interpretation
  • Max Cardinality changed from 1 to *
  • Change code system for extensibly bound codes from "http://terminology.hl7.org/CodeSystem/v2-0078" to "http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"
Observation.related
  • deleted

See the Full Difference for further information

This analysis is available as XML or JSON .

See R2 <--> R3 <--> R4 Conversion Maps (status = 34 48 tests that all execute ok. All tests pass round-trip testing and 15 23 r3 resources are invalid (58 (0 errors). ). Note: these have note yet been updated to be R3 to R4 )

Structure

Name Flags Card. Type Description & Constraints doco
. . Observation I N DomainResource Measurements and simple assertions
+ Rule: dataAbsentReason SHALL only be present if Observation.value[x] is not present
+ Rule: If Observation.code is the same as a an Observation.component.code then the value element associated with the code SHALL NOT be present
+ dataAbsentReason SHALL only be present if Observation.value[x] is not present Elements defined in Ancestors: id , meta , implicitRules , language , text , contained , extension , modifierExtension
. . . identifier Σ 0..* Identifier Business Identifier for observation
. . . basedOn Σ 0..* Reference ( CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest ) Fulfills plan, proposal or order
. . . partOf Σ 0..* Reference ( MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy ) Part of referenced event
. . . status ?! Σ 1..1 code registered | preliminary | final | amended +
ObservationStatus ( Required )
. . . category 0..* CodeableConcept Classification of type of observation
Observation Category Codes ( Preferred )
. . . code Σ 1..1 CodeableConcept Type of observation (code / type)
LOINC Codes ( Example )
. . . subject Σ 0..1 Reference ( Patient | Group | Device | Location ) Who and/or what this the observation is about
. . . focus Σ TU 0..1 0..* Reference ( Any ) The "focal point" of What the observation is about, when it is not about the subject of record
. . . context encounter Σ 0..1 Reference ( Encounter | EpisodeOfCare ) Healthcare event during which this observation is made
. . . effective[x] Σ 0..1 Clinically relevant time/time-period for observation
. . . . effectiveDateTime dateTime
. . . . effectivePeriod Period
. . . . effectiveTiming Timing
. . . . effectiveInstant instant
. . . issued Σ 0..1 instant Date/Time this version was made available
. . . performer Σ 0..* Reference ( Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson ) Who is responsible for the observation
. . . value[x] Σ I 0..1 Actual result
. . . . valueQuantity Quantity
. . . . valueCodeableConcept CodeableConcept
. . . . valueString string
. . . . valueBoolean boolean
. . . . valueInteger integer
. . . . valueRange Range
. . . . valueRatio Ratio
. . . . valueSampledData SampledData
. . . . valueTime time
. . . . valueDateTime dateTime
. . . . valuePeriod Period
. . . dataAbsentReason I 0..1 CodeableConcept Why the result is missing
DataAbsentReason ( Extensible )
. . . interpretation 0..1 0..* CodeableConcept High, low, normal, etc.
Observation Interpretation Codes ( Extensible )
. . comment . note 0..1 0..* string Annotation Comments about result the observation
. . . bodySite 0..1 CodeableConcept Observed body part
SNOMED CT Body Structures ( Example )
. . . method 0..1 CodeableConcept How it was done
Observation Methods ( Example )
. . . specimen 0..1 Reference ( Specimen ) Specimen used for this observation
. . . device 0..1 Reference ( Device | DeviceComponent | DeviceMetric ) (Measurement) Device
. . . referenceRange I 0..* BackboneElement Provides guide for interpretation
+ Rule: Must have at least a low or a high or text
. . . . low I 0..1 SimpleQuantity Low Range, if relevant
. . . . high I 0..1 SimpleQuantity High Range, if relevant
. . . . type 0..1 CodeableConcept Reference range qualifier
Observation Reference Range Meaning Codes ( Extensible Preferred )
. . . . appliesTo 0..* CodeableConcept Reference range population
Observation Reference Range Applies To Codes ( Example )
. . . . age 0..1 Range Applicable age range, if relevant
. . . . text 0..1 string Text based reference range in an observation
. . . hasMember Σ 0..* Reference ( Observation | QuestionnaireResponse | Sequence MolecularSequence ) Related resource that belongs to the Observation group
. . . derivedFrom Σ 0..* Reference ( DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | Sequence MolecularSequence ) Related measurements the observation is made from
. . . component Σ 0..* BackboneElement Component results
. . . . code Σ 1..1 CodeableConcept Type of component observation (code / type)
LOINC Codes ( Example )
. . . . value[x] Σ 0..1 Actual component result
. . . . . valueQuantity Quantity
. . . . . valueCodeableConcept CodeableConcept
. . . . . valueString string
. . . . . valueBoolean boolean
. . . . . valueInteger integer
. . . . . valueRange Range
. . . . . valueRatio Ratio
. . . . . valueSampledData SampledData
. . . . . valueTime time
. . . . . valueDateTime dateTime
. . . . . valuePeriod Period
. . . . dataAbsentReason I 0..1 CodeableConcept Why the component result is missing
DataAbsentReason ( Extensible )
. . . . interpretation 0..1 0..* CodeableConcept High, low, normal, etc.
Observation Interpretation Codes ( Extensible )
. . . . referenceRange 0..* see referenceRange Provides guide for interpretation of component result

doco Documentation for this format

UML Diagram ( Legend )

Observation ( DomainResource ) A unique identifier assigned to this observation identifier : Identifier [0..*] A plan, proposal or order that is fulfilled in whole or in part by this event event. For example, a MedicationRequest may require a patient to have laboratory test performed before it is dispensed basedOn : Reference [0..*] « CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest » A larger event of which this particular Observation is a component or step. For example, an observation as part of a procedure partOf : Reference [0..*] « MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy » The status of the result value (this element modifies the meaning of other elements) status : code [1..1] « Codes providing the status of an observation. (Strength=Required) ObservationStatus ! » A code that classifies the general type of observation being made category : CodeableConcept [0..*] « Codes for high level observation categories. (Strength=Preferred) Observation Category ObservationCategoryCodes ? » Describes what was observed. Sometimes this is called the observation "name" code : CodeableConcept [1..1] « Codes identifying names of simple observations. (Strength=Example) LOINC LOINCCodes ?? » The patient, or group of patients, location, or device whose characteristics (direct or indirect) are described by the this observation is about and into whose record the observation is placed. Comments: Indirect characteristics may be those If the actual focus of the observation is different from the subject (or a specimen, fetus, donor, other observer (for example a relative sample of, part, or EMT), region of the subject), the `focus` element or any observation made about the subject `code` itself specifies the actual focus of the observation subject : Reference [0..1] « Patient | Group | Device | Location » The actual focus of an observation when it is not the patient of record. The focus is point of attention when the observation record representing something or someone associated with the patient. It could be patient such as a spouse or spouse, parent, a fetus 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 focus : Reference [0..1] [0..*] « Any » The healthcare event (e.g. a patient and healthcare provider interaction) during which this observation is made context encounter : Reference [0..1] « Encounter | EpisodeOfCare » 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 effective[x] : Type [0..1] « dateTime | Period | Timing | instant » The date and time this version of the observation was made available to providers, typically after the results have been reviewed and verified issued : instant [0..1] Who was responsible for asserting the observed value as "true" performer : Reference [0..*] « Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson » The information determined as a result of making the observation, if the information has a simple value value[x] : Type [0..1] « Quantity | CodeableConcept | string | boolean | integer | Range | Ratio | SampledData | time | dateTime | Period » Provides a reason why the expected value in the element Observation.value[x] is missing dataAbsentReason : CodeableConcept [0..1] « Codes specifying why the result (`Observation.value[x]`) is missing. (Strength=Extensible) DataAbsentReason + » The A categorical assessment made based on the result of the observation. Intended as a simple compact code often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result. Otherwise known as abnormal flag an observation value. For example, high, low, normal interpretation : CodeableConcept [0..1] [0..*] « Codes identifying interpretations of observations. (Strength=Extensible) Observation Interpretation ObservationInterpretationCodes + » May include statements about significant, unexpected or unreliable values, or information Comments about the source of the value where this may be relevant to the interpretation of observation or the result results comment note : string Annotation [0..1] [0..*] Indicates the site on the subject's body where the observation was made (i.e. the target site) bodySite : CodeableConcept [0..1] « Codes describing anatomical locations. May include laterality. (Strength=Example) SNOMED CT Body Structures SNOMEDCTBodyStructures ?? » Indicates the mechanism used to perform the observation method : CodeableConcept [0..1] « Methods for simple observations. (Strength=Example) Observation Methods ObservationMethods ?? » The specimen that was used when this observation was made specimen : Reference [0..1] « Specimen » The device used to generate the observation data device : Reference [0..1] « Device | DeviceComponent | DeviceMetric » 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 hasMember : Reference [0..*] « Observation | QuestionnaireResponse | Sequence MolecularSequence » 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 derivedFrom : Reference [0..*] « DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | Sequence MolecularSequence » ReferenceRange 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) low : Quantity ( SimpleQuantity ) [0..1] 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) high : Quantity ( SimpleQuantity ) [0..1] Codes to indicate the what part of the targeted reference population it applies to. For example, the normal or therapeutic range type : CodeableConcept [0..1] « Code for the meaning of a reference range. (Strength=Extensible) (Strength=Preferred) Observation Reference Range M... ObservationReferenceRangeMean... + ? » 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 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 appliesTo : CodeableConcept [0..*] « Codes identifying the population the reference range applies to. (Strength=Example) Observation Reference Range A... ObservationReferenceRangeAppl... ?? » 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 age : Range [0..1] 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" text : string [0..1] Component Describes what was observed. Sometimes this is called the observation "code" code : CodeableConcept [1..1] « Codes identifying names of simple observations. (Strength=Example) LOINC LOINCCodes ?? » The information determined as a result of making the observation, if the information has a simple value value[x] : Type [0..1] « Quantity | CodeableConcept | string | boolean | integer | Range | Ratio | SampledData | time | dateTime | Period » Provides a reason why the expected value in the element Observation.component.value[x] is missing dataAbsentReason : CodeableConcept [0..1] « Codes specifying why the result (`Observation.value[x]`) is missing. (Strength=Extensible) DataAbsentReason + » The A categorical assessment made based on the result of the observation. Intended as a simple compact code often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result. Otherwise known as abnormal flag an observation value. For example, high, low, normal interpretation : CodeableConcept [0..1] [0..*] « Codes identifying interpretations of observations. (Strength=Extensible) Observation Interpretation ObservationInterpretationCodes + » Guidance on how to interpret the value by comparison to a normal or recommended range range. Multiple reference ranges are interpreted as an "OR". In other words, to represent two distinct target populations, two `referenceRange` elements would be used referenceRange [0..*] Guidance on how to interpret the value by comparison to a normal or recommended range referenceRange [0..*] 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 component [0..*]

XML Template

<Observation xmlns="http://hl7.org/fhir"> doco
 <!-- from Resource: id, meta, implicitRules, and language -->
 <!-- from DomainResource: text, contained, extension, and modifierExtension -->
 <identifier><!-- 0..* Identifier Business Identifier for observation --></identifier>
 <|

 <basedOn><!-- 0..* Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|

   MedicationRequest|NutritionOrder|ServiceRequest) Fulfills plan, proposal or order --></basedOn>
 <partOf><!-- 0..* Reference(MedicationAdministration|MedicationDispense|
   MedicationStatement|Procedure|Immunization|ImagingStudy) Part of referenced event --></partOf>
 <status value="[code]"/><!-- 1..1 registered | preliminary | final | amended + -->
 <category><!-- 0..* CodeableConcept Classification of  type of observation --></category>
 <code><!-- 1..1 CodeableConcept Type of observation (code / type) --></code>
 <</subject>
 <</focus>
 <</context>
 <</effective[x]>

 <subject><!-- 0..1 Reference(Patient|Group|Device|Location) Who and/or what the observation is about --></subject>
 <focus><!-- 0..* Reference(Any) What the observation is about, when it is not about the subject of record --></focus>
 <encounter><!-- 0..1 Reference(Encounter) Healthcare event during which this observation is made --></encounter>
 <effective[x]><!-- 0..1 dateTime|Period|Timing|instant Clinically relevant time/time-period for observation --></effective[x]>

 <issued value="[instant]"/><!-- 0..1 Date/Time this version was made available -->
 <performer><!-- 0..* Reference(Practitioner|PractitionerRole|Organization|
   CareTeam|Patient|RelatedPerson) Who is responsible for the observation --></performer>
 <|

 <value[x]><!-- ?? 0..1 Quantity|CodeableConcept|string|boolean|integer|Range|Ratio|

   SampledData|time|dateTime|Period Actual result --></value[x]>
 <dataAbsentReason><!-- ?? 0..1 CodeableConcept Why the result is missing --></dataAbsentReason>
 <</interpretation>
 <

 <interpretation><!-- 0..* CodeableConcept High, low, normal, etc. --></interpretation>
 <note><!-- 0..* Annotation Comments about the observation --></note>

 <bodySite><!-- 0..1 CodeableConcept Observed body part --></bodySite>
 <method><!-- 0..1 CodeableConcept How it was done --></method>
 <specimen><!-- 0..1 Reference(Specimen) Specimen used for this observation --></specimen>
 <</device>
 <

 <device><!-- 0..1 Reference(Device|DeviceMetric) (Measurement) Device --></device>
 <referenceRange>  <!-- 0..* Provides guide for interpretation -->

  <low><!-- ?? 0..1 Quantity(SimpleQuantity) Low Range, if relevant --></low>
  <high><!-- ?? 0..1 Quantity(SimpleQuantity) High Range, if relevant --></high>
  <type><!-- 0..1 CodeableConcept Reference range qualifier --></type>
  <</appliesTo>

  <appliesTo><!-- 0..* CodeableConcept Reference range population --></appliesTo>

  <age><!-- 0..1 Range Applicable age range, if relevant --></age>
  <text value="[string]"/><!-- 0..1 Text based reference range in an observation -->
 </referenceRange>
 <</hasMember>

 <hasMember><!-- 0..* Reference(Observation|QuestionnaireResponse|
   MolecularSequence) Related resource that belongs to the Observation group --></hasMember>
 <derivedFrom><!-- 0..* Reference(DocumentReference|ImagingStudy|Media|
   </derivedFrom>

   QuestionnaireResponse|Observation|MolecularSequence) Related measurements the observation is made from --></derivedFrom>
 <component>  <!-- 0..* Component results -->
  <code><!-- 1..1 CodeableConcept Type of component observation (code / type) --></code>
  <value[x]><!-- 0..1 Quantity|CodeableConcept|string|boolean|integer|Range|
    Ratio|SampledData|time|dateTime|Period Actual component result --></value[x]>
  <dataAbsentReason><!-- ?? 0..1 CodeableConcept Why the component result is missing --></dataAbsentReason>
  <</interpretation>

  <interpretation><!-- 0..* CodeableConcept High, low, normal, etc. --></interpretation>

  <referenceRange><!-- 0..* Content as for Observation.referenceRange Provides guide for interpretation of component result --></referenceRange>
 </component>
</Observation>

JSON Template

{doco
  "resourceType" : "Observation",
  // from Resource: id, meta, implicitRules, and language
  // from DomainResource: text, contained, extension, and modifierExtension
  "identifier" : [{ Identifier }], // Business Identifier for observation
  "|

  "basedOn" : [{ Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|

   MedicationRequest|NutritionOrder|ServiceRequest) }], // Fulfills plan, proposal or order
  "partOf" : [{ Reference(MedicationAdministration|MedicationDispense|
   MedicationStatement|Procedure|Immunization|ImagingStudy) }], // Part of referenced event
  "status" : "<code>", // R!  registered | preliminary | final | amended +
  "category" : [{ CodeableConcept }], // Classification of  type of observation
  "code" : { CodeableConcept }, // R!  Type of observation (code / type)
  "
  "
  "
  

  "subject" : { Reference(Patient|Group|Device|Location) }, // Who and/or what the observation is about
  "focus" : [{ Reference(Any) }], // What the observation is about, when it is not about the subject of record
  "encounter" : { Reference(Encounter) }, // Healthcare event during which this observation is made
  // effective[x]: Clinically relevant time/time-period for observation. One of these 4:
  "effectiveDateTime" : "<dateTime>",
  "effectivePeriod" : { Period },
  "effectiveTiming" : { Timing },
  "effectiveInstant" : "<instant>",

  "issued" : "<instant>", // Date/Time this version was made available
  "performer" : [{ Reference(Practitioner|PractitionerRole|Organization|
   CareTeam|Patient|RelatedPerson) }], // Who is responsible for the observation
  // value[x]: Actual result. One of these 11:
  "valueQuantity" : { Quantity },
  "valueCodeableConcept" : { CodeableConcept },
  "valueString" : "<string>",
  "valueBoolean" : <boolean>,
  "valueInteger" : <integer>,
  "valueRange" : { Range },
  "valueRatio" : { Ratio },
  "valueSampledData" : { SampledData },
  "valueTime" : "<time>",
  "valueDateTime" : "<dateTime>",
  "valuePeriod" : { Period },
  "dataAbsentReason" : { CodeableConcept }, // C? Why the result is missing
  "
  "

  "interpretation" : [{ CodeableConcept }], // High, low, normal, etc.
  "note" : [{ Annotation }], // Comments about the observation

  "bodySite" : { CodeableConcept }, // Observed body part
  "method" : { CodeableConcept }, // How it was done
  "specimen" : { Reference(Specimen) }, // Specimen used for this observation
  "
  "

  "device" : { Reference(Device|DeviceMetric) }, // (Measurement) Device
  "referenceRange" : [{ // Provides guide for interpretation

    "low" : { Quantity(SimpleQuantity) }, // C? Low Range, if relevant
    "high" : { Quantity(SimpleQuantity) }, // C? High Range, if relevant
    "type" : { CodeableConcept }, // Reference range qualifier
    "

    "appliesTo" : [{ CodeableConcept }], // Reference range population

    "age" : { Range }, // Applicable age range, if relevant
    "text" : "<string>" // Text based reference range in an observation
  }],
  "

  "hasMember" : [{ Reference(Observation|QuestionnaireResponse|
   MolecularSequence) }], // Related resource that belongs to the Observation group
  "derivedFrom" : [{ Reference(DocumentReference|ImagingStudy|Media|
   

   QuestionnaireResponse|Observation|MolecularSequence) }], // Related measurements the observation is made from
  "component" : [{ // Component results
    "code" : { CodeableConcept }, // R!  Type of component observation (code / type)
    // value[x]: Actual component result. One of these 11:
    "valueQuantity" : { Quantity },
    "valueCodeableConcept" : { CodeableConcept },
    "valueString" : "<string>",
    "valueBoolean" : <boolean>,
    "valueInteger" : <integer>,
    "valueRange" : { Range },
    "valueRatio" : { Ratio },
    "valueSampledData" : { SampledData },
    "valueTime" : "<time>",
    "valueDateTime" : "<dateTime>",
    "valuePeriod" : { Period },
    "dataAbsentReason" : { CodeableConcept }, // C? Why the component result is missing
    "

    "interpretation" : [{ CodeableConcept }], // High, low, normal, etc.

    "referenceRange" : [{ Content as for Observation.referenceRange }] // Provides guide for interpretation of component result
  }]
}

Turtle Template

@prefix fhir: <http://hl7.org/fhir/> .doco
[ a fhir:Observation;
  fhir:nodeRole fhir:treeRoot; # if this is the parser root
  # from Resource: .id, .meta, .implicitRules, and .language
  # from DomainResource: .text, .contained, .extension, and .modifierExtension
  fhir:Observation.identifier [ Identifier ], ... ; # 0..* Business Identifier for observation
  fhir:|

  fhir:Observation.basedOn [ Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|

  NutritionOrder|ServiceRequest) ], ... ; # 0..* Fulfills plan, proposal or order
  fhir:Observation.partOf [ Reference(MedicationAdministration|MedicationDispense|MedicationStatement|Procedure|
  Immunization|ImagingStudy) ], ... ; # 0..* Part of referenced event
  fhir:Observation.status [ code ]; # 1..1 registered | preliminary | final | amended +
  fhir:Observation.category [ CodeableConcept ], ... ; # 0..* Classification of  type of observation
  fhir:Observation.code [ CodeableConcept ]; # 1..1 Type of observation (code / type)
  fhir:
  fhir:
  fhir:
  # . One of these 3

  fhir:Observation.subject [ Reference(Patient|Group|Device|Location) ]; # 0..1 Who and/or what the observation is about
  fhir:Observation.focus [ Reference(Any) ], ... ; # 0..* What the observation is about, when it is not about the subject of record
  fhir:Observation.encounter [ Reference(Encounter) ]; # 0..1 Healthcare event during which this observation is made
  # Observation.effective[x] : 0..1 Clinically relevant time/time-period for observation. One of these 4

    fhir:Observation.effectiveDateTime [ dateTime ]
    fhir:Observation.effectivePeriod [ Period ]
    fhir:Observation.effectiveTiming [ Timing ]
    fhir:Observation.effectiveInstant [ instant ]

  fhir:Observation.issued [ instant ]; # 0..1 Date/Time this version was made available
  fhir:Observation.performer [ Reference(Practitioner|PractitionerRole|Organization|CareTeam|Patient|RelatedPerson) ], ... ; # 0..* Who is responsible for the observation
  # Observation.value[x] : 0..1 Actual result. One of these 11
    fhir:Observation.valueQuantity [ Quantity ]
    fhir:Observation.valueCodeableConcept [ CodeableConcept ]
    fhir:Observation.valueString [ string ]
    fhir:Observation.valueBoolean [ boolean ]
    fhir:Observation.valueInteger [ integer ]
    fhir:Observation.valueRange [ Range ]
    fhir:Observation.valueRatio [ Ratio ]
    fhir:Observation.valueSampledData [ SampledData ]
    fhir:Observation.valueTime [ time ]
    fhir:Observation.valueDateTime [ dateTime ]
    fhir:Observation.valuePeriod [ Period ]
  fhir:Observation.dataAbsentReason [ CodeableConcept ]; # 0..1 Why the result is missing
  fhir:
  fhir:

  fhir:Observation.interpretation [ CodeableConcept ], ... ; # 0..* High, low, normal, etc.
  fhir:Observation.note [ Annotation ], ... ; # 0..* Comments about the observation

  fhir:Observation.bodySite [ CodeableConcept ]; # 0..1 Observed body part
  fhir:Observation.method [ CodeableConcept ]; # 0..1 How it was done
  fhir:Observation.specimen [ Reference(Specimen) ]; # 0..1 Specimen used for this observation
  fhir:
  fhir:

  fhir:Observation.device [ Reference(Device|DeviceMetric) ]; # 0..1 (Measurement) Device
  fhir:Observation.referenceRange [ # 0..* Provides guide for interpretation

    fhir:Observation.referenceRange.low [ Quantity(SimpleQuantity) ]; # 0..1 Low Range, if relevant
    fhir:Observation.referenceRange.high [ Quantity(SimpleQuantity) ]; # 0..1 High Range, if relevant
    fhir:Observation.referenceRange.type [ CodeableConcept ]; # 0..1 Reference range qualifier
    fhir:

    fhir:Observation.referenceRange.appliesTo [ CodeableConcept ], ... ; # 0..* Reference range population

    fhir:Observation.referenceRange.age [ Range ]; # 0..1 Applicable age range, if relevant
    fhir:Observation.referenceRange.text [ string ]; # 0..1 Text based reference range in an observation
  ], ...;
  fhir:
  fhir:

  fhir:Observation.hasMember [ Reference(Observation|QuestionnaireResponse|MolecularSequence) ], ... ; # 0..* Related resource that belongs to the Observation group
  fhir:Observation.derivedFrom [ Reference(DocumentReference|ImagingStudy|Media|QuestionnaireResponse|Observation|
  MolecularSequence) ], ... ; # 0..* Related measurements the observation is made from
  fhir:Observation.component [ # 0..* Component results
    fhir:Observation.component.code [ CodeableConcept ]; # 1..1 Type of component observation (code / type)
    # Observation.component.value[x] : 0..1 Actual component result. One of these 11
      fhir:Observation.component.valueQuantity [ Quantity ]
      fhir:Observation.component.valueCodeableConcept [ CodeableConcept ]
      fhir:Observation.component.valueString [ string ]
      fhir:Observation.component.valueBoolean [ boolean ]
      fhir:Observation.component.valueInteger [ integer ]
      fhir:Observation.component.valueRange [ Range ]
      fhir:Observation.component.valueRatio [ Ratio ]
      fhir:Observation.component.valueSampledData [ SampledData ]
      fhir:Observation.component.valueTime [ time ]
      fhir:Observation.component.valueDateTime [ dateTime ]
      fhir:Observation.component.valuePeriod [ Period ]
    fhir:Observation.component.dataAbsentReason [ CodeableConcept ]; # 0..1 Why the component result is missing
    fhir:

    fhir:Observation.component.interpretation [ CodeableConcept ], ... ; # 0..* High, low, normal, etc.

    fhir:Observation.component.referenceRange [ See Observation.referenceRange ], ... ; # 0..* Provides guide for interpretation of component result
  ], ...;
]

Changes since DSTU2 Release 3

Observation
Observation.basedOn
  • Type changed from Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|NutritionOrder|ProcedureRequest|ReferralRequest) to Reference(CarePlan|DeviceRequest|ImmunizationRecommendation|MedicationRequest|NutritionOrder|ServiceRequest) Reference: Added Target Type ServiceRequest
  • Type Reference: Removed Target Types ProcedureRequest, ReferralRequest
Observation.partOf
  • Added Element
Observation.status
  • Change value set from http://hl7.org/fhir/ValueSet/observation-status to http://hl7.org/fhir/ValueSet/observation-status|4.0.0
Observation.focus
  • Added Element
Observation.encounter
  • Renamed from context to encounter
  • Type Reference: Removed Target Type EpisodeOfCare
Observation.effective[x]
  • Add Timing Types Timing, instant
Observation.performer
  • Type changed from Reference(Practitioner|Organization|Patient|RelatedPerson) to Reference(Practitioner|PractitionerRole|Organization|CareTeam|Patient|RelatedPerson) Reference: Added Target Types PractitionerRole, CareTeam
Observation.value[x]
  • Remove Attachment, Add Type integer
  • Remove Type Attachment
Observation.dataAbsentReason
  • Change value set from http://hl7.org/fhir/ValueSet/observation-valueabsentreason to http://hl7.org/fhir/ValueSet/data-absent-reason
  • Change code system for extensibly bound codes from "http://hl7.org/fhir/data-absent-reason" to "http://terminology.hl7.org/CodeSystem/data-absent-reason"
Observation.device Observation.interpretation
  • Max Cardinality changed from 1 to *
  • Change code system for extensibly bound codes from "http://terminology.hl7.org/CodeSystem/v2-0078" to "http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"
Observation.note
  • Renamed from comment to note
  • Max Cardinality changed from 1 to *
  • Type changed from Reference(Device|DeviceMetric) string to Reference(Device|DeviceComponent|DeviceMetric) Annotation
Observation.referenceRange.type
  • Remove Binding http://hl7.org/fhir/ValueSet/referencerange-meaning (extensible)
Observation.hasMember
  • Added Element
Observation.derivedFrom
  • Added Element
Observation.component.value[x]
  • Remove Attachment, Add Types boolean, Add integer
  • Remove Type Attachment
Observation.component.dataAbsentReason
  • Change value set from http://hl7.org/fhir/ValueSet/observation-valueabsentreason to http://hl7.org/fhir/ValueSet/data-absent-reason
  • Change code system for extensibly bound codes from "http://hl7.org/fhir/data-absent-reason" to "http://terminology.hl7.org/CodeSystem/data-absent-reason"
Observation.component.interpretation
  • Max Cardinality changed from 1 to *
  • Change code system for extensibly bound codes from "http://terminology.hl7.org/CodeSystem/v2-0078" to "http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"
Observation.related
  • deleted

See the Full Difference for further information

This analysis is available as XML or JSON .

See R2 <--> R3 <--> R4 Conversion Maps (status = 34 48 tests that all execute ok. All tests pass round-trip testing and 15 23 r3 resources are invalid (58 (0 errors). ). Note: these have note yet been updated to be R3 to R4 )

 

Alternate See the Profiles & Extensions and the alternate definitions: Master Definition XML + JSON , XML Schema / Schematron + JSON Schema , ShEx (for Turtle ) + see the extensions & the dependency analysis

Path Definition Type Reference
Observation.status Codes providing the status of an observation. Required ObservationStatus
Observation.category Codes for high level observation categories. Preferred Observation Category Codes ObservationCategoryCodes
Observation.code
Observation.component.code
Codes identifying names of simple observations. Example LOINC Codes LOINCCodes
Observation.dataAbsentReason
Observation.component.dataAbsentReason
Codes specifying why the result (`Observation.value[x]`) is missing. Extensible DataAbsentReason
Observation.interpretation
Observation.component.interpretation
Codes identifying interpretations of observations. Extensible Observation Interpretation Codes ObservationInterpretationCodes
Observation.bodySite Codes describing anatomical locations. May include laterality. Example SNOMED CT Body Structures SNOMEDCTBodyStructures
Observation.method Methods for simple observations. Example Observation Methods ObservationMethods
Observation.referenceRange.type Code for the meaning of a reference range. Extensible Preferred Observation Reference Range Meaning Codes ObservationReferenceRangeMeaningCodes
Observation.referenceRange.appliesTo Codes identifying the population the reference range applies to. Example Observation Reference Range Applies To Codes ObservationReferenceRangeAppliesToCodes

id Level Location Description Expression
obs-3 : On Observation.referenceRange: Rule Observation.referenceRange Must have at least a low or a high or text ( expression on Observation.referenceRange: low.exists() or high.exists() or text.exists() )
obs-6 : Rule (base) dataAbsentReason SHALL only be present if Observation.value[x] is not present ( expression : dataAbsentReason.empty() or value.empty() )
obs-7 : Rule (base) If Observation.code is the same as a an Observation.component.code then the value element associated with the code SHALL NOT be present ( expression : value.empty() or component.code.where( (coding.code = %resource.code.coding.code) and (coding.system = %resource.code.coding.system)).empty() )

At its simplest, a resource instances instance can consist of only a code and a value, and status flag. The relevance of other properties will vary based on the type of observation. Profiles are created to provide guidance on capturing certain types of observations for a given use case. The Observation resource focuses on the level of detail captured by most systems. However, for a given use case there may be additional constraints and additional information relevant in certain circumstances. As with other resources, extensions can be used to introduce this additional complexity.

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. However, three attributes may be used for representing the focus of the observation if it is not the subject itself. The specimen and bodySite elements are used to represent measurements taken on subject samples or anatomic and morphological locations, and focus represents specific aspect of the subject that are the point of attention such as another observation or a device implanted in a patient.

Many observations have important relationships to other observations and need to be grouped together. These structures have been defined to do this: DiagnosticReport and DiagnosticReport.result , Observation and the elements: Observation.component , Observation.hasMember and Observation.derivedFrom . The sections below provides guidance around which structure to use. Because the idea of what to group together is often highly contextual and based upon the end user's point of view, the choice of which structure to use will be driven by jurisdiction, organizational practice and context. Profiling will normally be necessary for implementation.

DiagnosticReport relates directly to an order (ServiceRequest). The DiagnosticReport.code names the panel and serves as the grouping element, which is traditionally referred to as a "panel" or "battery" by laboratories. The DiagnosticReport.result element references the individual observations. Several examples demonstrate observation grouping using DiagnosticReport as the grouping structure.

Observation.component is used for any supporting result that cannot reasonably be interpreted and used outside the scope of the Observation it is a component of. Component observations may make up the separate and individual parts of the observation or may provide qualifying information to Observation.code and may only be able to be understood in relation to the Observation.code (for example, see the $stats operation ). Therefore all code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation. Components should only be used when there is only one method, one observation, one performer, one device, and one time. Some use cases for using this structure include:

  1. Observations that are commonly produced and interpreted together. For example, systolic and diastolic blood pressure are represented as a single Blood pressure panel .
  2. Assessment tool results that are commonly produced and interpreted together. For example, a newborn Apgar score that is a single Observation with five components.
  3. Representing multiple answers to a question ( relationship and boundaries between Observation and Questionnaire/QuestionnaireResponse). For example, reporting the types of alcohol consumed by a patient

On the other hand, any observations that are clinically relevant outside the context of being a component of another observation should be represented by separate Observation resources. For example a Body Mass Index (BMI) Observation should not contain components for height and weight because they are clinically relevant observations on their own and should be represented by separate Observation resources. See the section below on how to relate independent Observations.

Observation.hasMember and Observation.derivedFrom and the core extensions: Observation-sequel-to Observation-sequelTo and Observation-replaces are used for any supporting result that can be interpreted and used on its own and has one or more different values for method, observation, performer, device, time, and/or error conditions. Two common use cases for using this structure are:

  1. For grouping related observations such as for a "panel" or "battery". In this case the Observation.code represents the "panel" code, typically Observation.value[x] is not present, and the set of member Observations are listed in Observation.hasMember . This structure permits nested grouping when used with DiagnosticReport (e.g. complex micro isolate and sensitivities report ).
  2. When linking to other Observations from which an Observation is derived. In this case both Observation.code and Observation.value[x] are present, and the linked observations are listed in Observation.derivedFrom . An example of this would be a Body Mass Index (BMI) Observation where the height and weight measurements are referenced.

When a result value is a represented as a predefined concept using a code, valueCodeableConcept is used. This element is bound to a value set comprised of a standard nomenclature such as SNOMED CT or a source system ("local") coded result values.

Results may be coded in multiple value sets based on different code systems and these may be mapped using the ConceptMap resource and/or given as translations additional codings directly in the element as shown in the example below.

For example the LOINC 43304-5 Chlamydia trachomatis rRNA [Presence] in Unspecified specimen by Probe and target amplification method is typically associated with coded presence/absence concepts. Using the coded value for 'negative' with a standard code translation, valueCodeableConcept would be:

	"valueCodeableConcept": {
		"coding": [
			{
				"system": "http://snomed.info/sct",
				"code": "260385009",
				"display": "Negative"
			}, {
				"system": "https://acme.lab/resultcodes",
				"code": "NEG",
				"display": "Negative"
			}
		],
		"text": "Negative for Chlamydia Trachomatis rRNA"
	}

When the data element is usually coded or the type associated with the code element defines a coded value, use valueCodeableConcept even if there is no appropriate code and only free text is available. For example using text only, the valueCodeableConcept element would be:

	"valueCodeableConcept": {
		"text": "uncoded free text result"
	}

When a coded answer list includes a concept code for "other" and there is a free text description of the concept, the valueCodeableConcept.text element should be used to capture the full meaning of the source. In the example below, the answer code "Other" is provided in the valueCodeableConcept element and the text value supplied value in the CodeableConcept.text element.

{
	"resourceType": "Observation",
	... snip ...
	"code": {
		"coding": [
			{
				"system": "http://loinc.org",
				"code": "74076-1",
				"display": "Medication or substance involved"
			}
		]
	},
	.. snip ...
	"valueCodeableConcept": {
		"coding": [
			{
				"system": "http://loinc.org",
				"code": " LA20343-2",
				"display": "Other substance: PLEASE SPECIFY"
			}
		],
		"text": "Other: Blue pills I found under my couch"
	}
	.. snip ...
}

A recurring issue for many observation events, regardless of the particular pattern, is determining how to populate observation.code and observation.value. While this is typically straight-forward for laboratory observations, it can get blurry for other types of observations, such as findings and disorders, family history observations, etc. This discussion focuses on the way in which the coded representation of such statements is expressed using the Observation.code and Observation.value elements.

There are two distinct facets that are central to a FHIR Observations:

  • The action taken to make the finding and/or the property about which the property was observed. For example: measurement of blood hemoglobin.
  • The result of the observation. For example: 14 g/dl.

Several different ways of representing the same information exist using different combinations of the Observation.code and Observation.value . Unconstrained use of the alternatives presents a major challenge for computation of semantic equivalence and for safe interpretation of observations originating from different applications and users. The following four patterns could reasonably represent the same case. Considering that the Observation resource needs to support many use cases, the appropriate place to define the specific pattern is expected to be done through profiles and implementation guides as specified by the jurisdictions and/or organizations implementing FHIR:

  1. Observation.code represents the nature of the observation and the Observation.value a code represents the non-numeric result value. These are two distinct facets that are central to a FHIR Observations. For example:
    • code=[Examination]
    • value=[Abdomen tender]
  2. Observation.code is nearly identical to 1) above, but the level of granularity is shifted from the value to code. For example:
    • code=[Abdominal examination]
    • value=[Tenderness]
  3. The Observation.code is also expressed in a way that does not specify the observation action but indicates a statement about findings reduced to a single name (or term), as in the above item. In this example, the Observation.value is present and "qualifies" the finding typically confirming or refuting it. For example:
    • code=[Abdominal tenderness]
    • value=[found/true]
  4. in this example the Observation.code is expressed in a way that does not specify the observation action but indicates a statement about findings reduced to a single name (or term). In this particular example in that context, the Observation.value is omitted. For example:
    • code=[Abdominal tenderness]
    • value element is omitted
  1. Recommended rules for case 1 and 2 patterns:
    • The Observation.code is preferably a LOINC concept code.
      • If a SNOMED CT concept code is used, the expression SHOULD represent a 363787002 (Observable entity(Observable entity)) or 386053000 (Evaluation procedure(evaluation procedure))
    • For non-numeric values, the Observation.value is preferably a SNOMED CT concept code.
  2. Recommended rules for case 3 pattern:
    • The Observation.code is preferably a LOINC or SNOMED CT concept code.
      • If a SNOMED CT concept code is used, the expression SHOULD represent a 404684003 (Clinical finding (finding)) , 413350009 (Finding with explicit context(finding)), or 272379006 (Event(event)).
    • The Observation.value is represented by either
  3. Recommended rules for case 4 pattern:
    • The Observation.code is preferably a SNOMED CT concept code where the concept is-a 404684003 (Clinical finding (finding)) , 413350009 (Finding with explicit context(finding)), or 272379006 (Event(event)).
    • The Observation.value is omitted. The default interpretation is the concept (single code or expression) represented in Observation.code is present in the patient. A An Observation.dataAbsentReason value of 'clinical-finding' SHOULD be used to indicate why the expected value is missing.
  4. SHOULD NOT use the Assertion pattern as described in HL7 Version 3 Implementation Guide: TermInfo - Using SNOMED CT in CDA R2 Models, Release 1 . ( The code is 'ASSERTION' and the value is a SNOMED CT concept or expression )

The following list provides guidance on using codes or other observations to provide additional context that may alter how an observation is interpreted.:

  1. If possible, use the most specific code you can

    e.g.:

    {
    "resourceType": "Observation",
    ... snip ...
    "code": {
    	"coding": [
    		{
    			"system": "http://loinc.org",
    			"code": "6689-4",
    			"display": "Glucose [Mass/​volume] in Blood --2 hours post meal"
    		}
    	]
    },
    ... snip ...
    }
    
  2. Alternatively, use additional codes in Observation.code as described above .

    e.g.: Observation.code = coding-1: 59408-5 Oxygen saturation in Arterial blood by Pulse oximetry, coding-2: 20564-1 Oxygen saturation in Blood

    {
    "resourceType": "Observation",
    ... snip ...
    "code": {
    	"coding": [
    		{
    			"system": "http://loinc.org",
    			"code": "59408-5",
    			"display": "Oxygen saturation in Arterial blood by Pulse oximetry"
    		},
    		{
    			"system": "http://loinc.org",
    			"code": "20564-1",
    			"display": "Oxygen saturation in Blood"
    		}
    	]
    },
    ... snip ...
    }
    
  3. As described above , observations are typically grouped together to provide additional information needed for correctly understanding and interpreting the observation. As an alternative to grouping observations, extensions may be used to provide references to other observations needed for understanding and interpreting an observation.

Note: We are seeking input from the implementer community in evaluating existing Observation Extensions for this purpose

Feedback here .

  • The element, Observation.value[x], has a variable name depending on the type as follows:
    • valueQuantity
    • valueCodeableConcept
    • valueString
    • valueBoolean
    • valueInteger
    • valueRange
    • valueRatio
    • valueSampledData
    • valueTime
    • valueDateTime
    • valuePeriod

  • See above section on Using codes for result values
  • The Boolean data type is rarely used for value[x] because most observations result values are never truly Boolean due to exceptional values such as "unknown", therefore they should use the CodeableConcept data type instead and select codes from http://hl7.org/fhir/ValueSet/v2-0136 http://terminology.hl7.org/ValueSet/v2-0136 (these "yes/no" concepts can be mapped to the display name "true/false" or other mutually exclusive terms that may be needed")
  • The special values "E" (error), "L" (below detection limit) and "U" (above detection limit) can be used are in the SampledData data type. However, when using valueQuantity in an observation for above and below detection limit values, valueQuantity should be used by stating the limit along with the comparator. In addition, when there is an error the dataAbsentReason element should be used with the appropriate value ('error' or 'NaN'). For example if the value was below the lower limit of detection of <2.0 mmol/L the valueQuantity would be:
    	"valueQuantity": {
    		"value": 2.0,
    		"comparator": "<",
    		"unit": "mmol/l",
    		"system": "http://unitsofmeasure.org",
    		"code": "mmol/L"
    	}
    
    If the value was "NaN" (i.e. an error) the valueCodeableConcept element would be absent and dataAbsentReason element would be:
    	"dataAbsentReason": {
    		"coding": [
    			{
    				"system": "http://hl7.org/fhir/data-absent-reason",
    
    				"system": "http://terminology.hl7.org/CodeSystem/data-absent-reason",
    
    				"code": "NaN",
    				"display": "Not a Number"
    			}
    		]
    	}
    
  • Because there are multiple types allowed for the value element, multiple value search parameters are defined. There is no standard parameter for searching values of type Ratio
10.1.4.6

The effectiveDateTime or effectivePeriod is the time that the observation is most relevant as an observation of the subject. For a biological subject (e.g. a human patient), this is the physiologically relevant time of the observation. In the case of an observation using a specimen, this represents the start and end of the specimen collection (e.g. 24-hour Urine Sodium), but if the collection time is sufficiently short, this is reported as a point in time value (e.g. normal venipuncture). In the case of an observation obtained directly from a subject (e.g. BP, Chest X-ray), this is the start and end time of the observation process, which again, is often reported as a single point in time.

10.1.4.7

Most common observations will only have one generic reference range. Reference ranges may be useful for laboratory tests and other measures like systolic blood pressuer pressure but will have little relevance for something like "pregnancy status". 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.

10.1.4.8

If a measurement or test could not be completed (for example if the specimen is unsatisfactory or the provider cancelled the order), then the status value should be updated to "cancelled" and the specific details given - preferably as coded values in the dataAbsentReason or valueCodeableConcept element. Additional information may be provided in comments the `note` element as well. The specimen reject example demonstrates this using a coded value for unsatisfactory specimen in dataAbsentReason.

Genetic reporting makes heavy use of the DiagnosticReport and Observation resources. An implementation guide describing how to represent genetic results can be found here .

The lastn query operation meets the common need for searching for the most recent or "last known" Observations for a subject. Examples where this query could be used:

  • Fetch the last 5 temperatures for a patient to view trends
  • Get the most recent laboratory results for patient
  • Fetch the last 3 results for all vitals for a patient

See the Last N Observations Query section in the Observation resource operations page for more information and examples

The stats operation performs a set of statistical calculations on a set of clinical measurements such as a blood pressure as stored on the server. This operation is focused on Observation resources with valueQuantity elements that have UCUM unit codes. Examples where this operation could be used:

  • Get the average, min, max and count of a series of BP measurements for a patient
  • Determine 20th or 80th percentile on a set of measurements over a time period
See the Observation Statistics section in the Observation resource operations page for more information and examples

Search parameters for this resource. The common parameters also apply. See Searching for more information about searching in REST, messaging, and services.

Name Type Description Expression In Common
based-on TU reference Reference to the service request. Observation.basedOn
( CarePlan , MedicationRequest , NutritionOrder , DeviceRequest , ServiceRequest , ImmunizationRecommendation )
category TU token The classification of the type of observation Observation.category
code TU token The code of the observation type Observation.code 8 13 Resources
code-value-concept TU composite Code and coded value parameter pair Observation On Observation:
  code: code
  value-concept: value.as(CodeableConcept)
code-value-date TU composite Code and date/time value parameter pair Observation On Observation:
  code: code
  value-date: value.as(DateTime) | value.as(Period)
code-value-quantity TU composite Code and quantity value parameter pair Observation On Observation:
  code: code
  value-quantity: value.as(Quantity)
code-value-string TU composite Code and string value parameter pair Observation On Observation:
  code: code
  value-string: value.as(string)
combo-code TU token The code of the observation type or component type Observation.code | Observation.component.code
combo-code-value-concept TU composite Code and coded value parameter pair, including in components On Observation | Observation.component Observation.component:
  combo-code: code
  combo-value-concept: value.as(CodeableConcept)
combo-code-value-quantity TU composite Code and quantity value parameter pair, including in components On Observation | Observation.component Observation.component:
  combo-code: code
  combo-value-quantity: value.as(Quantity)
combo-data-absent-reason TU token The reason why the expected value in the element Observation.value[x] or Observation.component.value[x] is missing. Observation.dataAbsentReason | Observation.component.dataAbsentReason
combo-value-concept TU token The value or component value of the observation, if the value is a CodeableConcept Observation.value.as(CodeableConcept) (Observation.value as CodeableConcept) | Observation.component.value.as(CodeableConcept) (Observation.component.value as CodeableConcept)
combo-value-quantity TU quantity The value or component value of the observation, if the value is a Quantity, or a SampledData (just search on the bounds of the values in sampled data) Observation.value.as(Quantity) (Observation.value as Quantity) | Observation.component.value.as(Quantity) (Observation.value as SampledData) | (Observation.component.value as Quantity) | (Observation.component.value as SampledData)
component-code TU token The component code of the observation type Observation.component.code
component-code-value-concept TU composite Component code and component coded value parameter pair Observation.component On Observation.component:
  component-code: code
  component-value-concept: value.as(CodeableConcept)
component-code-value-quantity TU composite Component code and component quantity value parameter pair Observation.component On Observation.component:
  component-code: code
  component-value-quantity: value.as(Quantity)
component-data-absent-reason TU token The reason why the expected value in the element Observation.component.value[x] is missing. Observation.component.dataAbsentReason
component-value-concept TU token The value of the component observation, if the value is a CodeableConcept Observation.component.value.as(CodeableConcept) (Observation.component.value as CodeableConcept)
component-value-quantity TU quantity The value of the component observation, if the value is a Quantity, or a SampledData (just search on the bounds of the values in sampled data) Observation.component.value.as(Quantity) context reference Healthcare event (Episode-of-care or Encounter) related to the observation Observation.context ( EpisodeOfCare , Encounter ) (Observation.component.value as Quantity) | (Observation.component.value as SampledData)
data-absent-reason TU token The reason why the expected value in the element Observation.value[x] is missing. Observation.dataAbsentReason
date TU date Obtained date/time. If the obtained element is a period, a date that falls in the period Observation.effective 17 Resources
derived-from TU reference Related measurements the observation is made from Observation.derivedFrom
( Media , Observation , ImagingStudy , Sequence MolecularSequence , QuestionnaireResponse , DocumentReference )
device TU reference The Device that generated the observation data. Observation.device
( DeviceComponent , Device , DeviceMetric )
encounter TU reference Encounter related to the observation Observation.context Observation.encounter
( Encounter )
12 Resources
focus TU reference The focus of an observation when the focus is not the patient of record. Observation.focus
(Any)
has-member TU reference Related resource that belongs to the Observation group Observation.hasMember
( Observation , Sequence MolecularSequence , QuestionnaireResponse )
identifier TU token The unique id for a particular observation Observation.identifier 26 30 Resources
method TU token The method used for the observation Observation.method
part-of TU reference Part of referenced event Observation.partOf
( Immunization , MedicationDispense , MedicationAdministration , Procedure , ImagingStudy , MedicationStatement )
patient TU reference The subject that the observation is about (if patient) Observation.subject Observation.subject.where(resolve() is Patient)
( Patient )
29 33 Resources
performer TU reference Who performed the observation Observation.performer
( Practitioner , Organization , CareTeam , Patient , PractitionerRole , RelatedPerson )
specimen TU reference Specimen used for this observation Observation.specimen
( Specimen )
status TU token The status of the observation Observation.status
subject TU reference The subject that the observation is about Observation.subject
( Group , Device , Patient , Location )
value-concept TU token The value of the observation, if the value is a CodeableConcept Observation.value.as(CodeableConcept) (Observation.value as CodeableConcept)
value-date TU date The value of the observation, if the value is a date or period of time Observation.value.as(dateTime) (Observation.value as dateTime) | Observation.value.as(Period) (Observation.value as Period)
value-quantity TU quantity The value of the observation, if the value is a Quantity, or a SampledData (just search on the bounds of the values in sampled data) Observation.value.as(Quantity) (Observation.value as Quantity) | (Observation.value as SampledData)
value-string TU string The value of the observation, if the value is a string, and also searches in CodeableConcept.text Observation.value.as(string) (Observation.value as string) | (Observation.value as CodeableConcept).text