The Observation resource implements the FHIR R4 Observation specification and the following US Core v3.1.1 profiles:

Fields

Name Type Cardinality Required Description
identifier Identifier 0..*   Business Identifier for observation
basedOn Reference 0..*   Fulfills plan, proposal or order
partOf Reference 0..*   Part of referenced event
status code 1..1 * registered | preliminary | final | amended +
category CodeableConcept 1..* * Classification of type of observation
code CodeableConcept 1..1 * Type of observation (code / type)
subject Reference 1..1 * Who and/or what this is about
focus Reference 0..*   What request fulfills
encounter Reference 0..1   Healthcare event during which this observation is made
effectiveDateTime dateTime 0..1   Clinically relevant time/time-period for observation
effectivePeriod Period 0..1   Clinically relevant time/time-period for observation
effectiveTiming Timing 0..1   Clinically relevant time/time-period for observation
effectiveInstant instant 0..1   Clinically relevant time/time-period for observation
issued instant 0..1   Date/Time this was made available
performer Reference 0..*   Who is responsible for the observation
valueQuantity Quantity 0..1   Actual result
valueCodeableConcept CodeableConcept 0..1   Actual result
valueString string 0..1   Actual result
valueBoolean boolean 0..1   Actual result
valueInteger integer 0..1   Actual result
valueRange Range 0..1   Actual result
valueRatio Ratio 0..1   Actual result
valueSampledData SampledData 0..1   Actual result
valueTime time 0..1   Actual result
valueDateTime dateTime 0..1   Actual result
valuePeriod Period 0..1   Actual result
dataAbsentReason CodeableConcept 0..1   Why the result is missing
interpretation CodeableConcept 0..*   High, low, normal, etc.
note string 0..1   Comments about the observation
bodySite CodeableConcept 0..1   Observed body part
method CodeableConcept 0..1   How it was done
specimen Reference 0..1   Specimen used for this observation
device Reference 0..1   (Measurement) Device
referenceRange BackboneElement 0..*   Provides guide for interpretation
hasMember Reference 0..*   Who is responsible for the observation
component BackboneElement 0..*   Component results
dataAbsentReason CodeableConcept 0..1 Why the result is missing  

Interactions

Read

Get an Observation entry by id

GET /Observation/:id

Query Observation resources

GET /Observation?:query_parameters

Parameters

Name Type Description
date date Obtained date/time. If the obtained element is a period, a date that falls in the period
code token The code of the observation type
subject reference The subject that the observation is about
value-concept token The value of the observation, if the value is a CodeableConcept
value-date date The value of the observation, if the value is a date or period of time
patient reference The subject that the observation is about (if patient)
specimen reference Specimen used for this observation
value-string string The value of the observation, if the value is a string, and also searches in CodeableConcept.text
performer reference Who performed the observation
value-quantity 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)
encounter reference Encounter related to the observation
related-type token has-membertarge | derived-from | sequel-to | replaces | qualified-by | interfered-by
related-target reference Resource that is related to this one
category token The classification of the type of observation
status token The status of the observation
_include   Observation:subject | Observation:context | Observation:performer | Observation:related-target
_revinclude   Provenance:target

Errors

Code Description
400 Invalid parameters
404 Resource not found

Profiles

All US Core Observation profiles and the FHIR VitalSigns profile are supported:

  • status is required
  • subject is required
  • code is required
  • category[0].coding[0].system=" http://terminology.hl7.org/CodeSystem/observation-category" category[0].coding[0].code="laboratory" code should be a LOINC code describing the laboratory test name - Binding value[x] should use SnomedCT for coded results and UCUM for coded quantity units if the is no component or hasMember field then either value[x] or dataAbsentReason must be present

    Example

     {
     "resourceType": "Observation",
     "status": "final",
     "category": [
         {
         "coding": [
             {
             "system": "http://terminology.hl7.org/CodeSystem/observation-category",
             "code": "laboratory",
             "display": "Laboratory"
             }
         ],
         "text": "Laboratory"
         }
     ],
     "code": {
         "coding": [
         {
             "code": "786-4",
             "system": "http://loinc.org",
             "display": "MCHC [Mass/volume] by Automated count"
         }
         ],
         "text": "MCHC [Mass/volume] by Automated count"
     },
     "subject": {
         "reference": "Patient/bcfa83df-ee8c-9721-cc07-bdcfc2b1e3f2"
     },
     "effectiveDateTime": "1983-06-29T00:56:44-04:00",
     "issued": "1983-06-29T00:56:44.801-04:00",
     "valueQuantity": {
         "value": 35.665,
         "system": "http://unitsofmeasure.org",
         "code": "g/dL",
         "unit": "g/dL"
     },
     "id": "ae5ecf93-ad2a-e841-e31b-7bc4fdbcb89d"
     }
    
  • code.coding[0].system=" http://loinc.org" code.coding[0].code="59576-9" valueQuantity.system.uri="http://unitsofmeasure.org" valueQuantity.code="%"

    Example

     {
     "resourceType": "Observation",
     "status": "final",
     "category": [
         {
         "coding": [
             {
             "system": "http://terminology.hl7.org/CodeSystem/observation-category",
             "code": "vital-signs",
             "display": "Vital Signs"
             }
         ],
         "text": "Vital Signs"
         }
     ],
     "code": {
         "coding": [
         {
             "code": "59576-9",
             "system": "http://loinc.org",
             "display": "Body mass index (BMI) [Percentile] Per age and gender"
         }
         ],
         "text": "Body mass index (BMI) [Percentile] Per age and gender"
     },
     "subject": {
         "reference": "Patient/bcfa83df-ee8c-9721-cc07-bdcfc2b1e3f2"
     },
     "effectiveDateTime": "1961-02-21T23:56:44-05:00",
     "issued": "1961-02-21T23:56:44.801-05:00",
     "valueQuantity": {
         "value": 61.202,
         "system": "http://unitsofmeasure.org",
         "code": "%",
         "unit": "%"
     },
     "id": "7c764cc1-1d0f-90d0-1010-ef7f53f406ce"
     }
    
  • code.coding[0].system=" http://loinc.org" code.coding[0].code="8289-1" valueQuantity.system.uri="http://unitsofmeasure.org" valueQuantity.code="%"

    Example

     {
     "resourceType": "Observation",
     "status": "final",
     "category": [
         {
         "coding": [
             {
             "system": "http://terminology.hl7.org/CodeSystem/observation-category",
             "code": "vital-signs",
             "display": "Vital Signs"
             }
         ],
         "text": "Vital Signs"
         }
     ],
     "code": {
         "coding": [
         {
             "code": "8289-1",
             "system": "http://loinc.org",
             "display": "Head Occipital-frontal circumference Percentile"
         }
         ]
     },
     "subject": {
         "reference": "Patient/bcfa83df-ee8c-9721-cc07-bdcfc2b1e3f2"
     },
     "effectiveDateTime": "1942-01-22T00:00:00+00:00",
     "dataAbsentReason": {
         "coding": [
         {
             "code": "unknown",
             "system": "http://terminology.hl7.org/CodeSystem/data-absent-reason",
             "display": "unknown"
         }
         ],
         "text": "unknown"
     },
     "id": "5fdf86c1-0af1-459e-973d-1e9a9373dbb6"
     }
    
  • US Core Pediatric Weight for Height Observation Profile (link)(https://hl7.org/fhir/us/core/STU3.1.1/StructureDefinition-pediatric-weight-for-height.html)

    code.coding[0].system=" http://loinc.org" code.coding[0].code="77606-2" valueQuantity.system.uri="http://unitsofmeasure.org" valueQuantity.code="%"

    Example

     {
     "resourceType": "Observation",
     "status": "final",
     "category": [
         {
         "coding": [
             {
             "system": "http://terminology.hl7.org/CodeSystem/observation-category",
             "code": "vital-signs",
             "display": "Vital Signs"
             }
         ],
         "text": "Vital Signs"
         }
     ],
     "code": {
         "coding": [
         {
             "code": "77606-2",
             "system": "http://loinc.org",
             "display": "Weight-for-length Per age and sex"
         }
         ],
         "text": "Weight-for-length Per age and sex"
     },
     "subject": {
         "reference": "Patient/bcfa83df-ee8c-9721-cc07-bdcfc2b1e3f2"
     },
     "effectiveDateTime": "1943-03-03T00:56:44-04:00",
     "issued": "1943-03-03T00:56:44.801-04:00",
     "valueQuantity": {
         "value": 92.037,
         "system": "http://unitsofmeasure.org",
         "code": "%",
         "unit": "%"
     },
     "id": "f72fe059-3b38-4634-9904-4cf111194d83"
     }
    
  • code.coding[0].system="http://loinc.org" code.coding[0].code="59408-5" component[0].code.coding[0].system="http://loinc.org" component[0].code.coding[0].code="3151-8" component[0].valueQuantity.value=<numeric_flow_rate_value> component[0].valueQuantity.system.uri="http://unitsofmeasure.org" component[0].valueQuantity.code="L/min" component[0].code.coding[0].system="http://loinc.org" component[0].code.coding[0].code="3150-0" component[0].valueQuantity.value=<numeric_concentration_value> component[0].valueQuantity.system.uri="http://unitsofmeasure.org" component[0].valueQuantity.code="%"

    Example

     {
     "resourceType": "Observation",
     "status": "final",
     "category": [
         {
         "coding": [
             {
             "system": "http://terminology.hl7.org/CodeSystem/observation-category",
             "code": "vital-signs",
             "display": "Vital Signs"
             }
         ],
         "text": "Vital Signs"
         }
     ],
     "code": {
         "coding": [
         {
             "code": "2708-6",
             "system": "http://loinc.org",
             "display": "Oxygen saturation in Arterial blood"
         },
         {
             "code": "59408-5",
             "system": "http://loinc.org",
             "display": "Oxygen saturation in Arterial blood by Pulse oximetry"
         }
         ],
         "text": "Oxygen saturation in Arterial blood"
     },
     "subject": {
         "reference": "Patient/bcfa83df-ee8c-9721-cc07-bdcfc2b1e3f2"
     },
     "effectiveDateTime": "1995-06-27T03:00:44-04:00",
     "issued": "1995-06-27T03:00:44.801-04:00",
     "valueQuantity": {
         "value": 82,
         "system": "http://unitsofmeasure.org",
         "code": "%",
         "unit": "%"
     },
     "component": [
         {
         "code": {
             "coding": [
             {
                 "system": "http://loinc.org",
                 "code": "3151-8",
                 "display": "Inhaled oxygen flow rate"
             }
             ],
             "text": "Inhaled oxygen flow rate"
         },
         "dataAbsentReason": {
             "coding": [
             {
                 "system": "http://terminology.hl7.org/CodeSystem/data-absent-reason",
                 "code": "unknown",
                 "display": "Unknown"
             }
             ],
             "text": "Unknown"
         }
         },
         {
         "code": {
             "coding": [
             {
                 "system": "http://loinc.org",
                 "code": "3150-0",
                 "display": "Inhaled oxygen concentration"
             }
             ],
             "text": "Inhaled oxygen concentration"
         },
         "dataAbsentReason": {
             "coding": [
             {
                 "system": "http://terminology.hl7.org/CodeSystem/data-absent-reason",
                 "code": "unknown",
                 "display": "Unknown"
             }
             ],
             "text": "Unknown"
         }
         }
     ],
     "id": "207849f0-ed9f-42c9-a1de-808c1ebcf302"
     }
    
  • issued is mandatory code.coding[0].system=" http://loinc.org" code.coding[0].code="72166-2" valueCodeableConcept is mandatory, Binding

    Example

     {
     "resourceType": "Observation",
     "status": "final",
     "category": [
         {
         "coding": [
             {
             "system": "http://terminology.hl7.org/CodeSystem/observation-category",
             "code": "other",
             "display": "Other"
             }
         ],
         "text": "Other"
         }
     ],
     "code": {
         "coding": [
         {
             "code": "72166-2",
             "system": "http://loinc.org",
             "display": "Tobacco smoking status NHIS"
         }
         ],
         "text": "Tobacco smoking status NHIS"
     },
     "subject": {
         "reference": "Patient/bcfa83df-ee8c-9721-cc07-bdcfc2b1e3f2"
     },
     "effectiveDateTime": "1960-02-16T23:56:44-05:00",
     "issued": "1960-02-16T23:56:44.801-05:00",
     "valueCodeableConcept": {
         "coding": [
         {
             "system": "http://snomed.info/sct",
             "code": "266919005",
             "display": "Never smoker"
         }
         ],
         "text": "Never smoker"
     },
     "id": "b34a0382-c0af-1be5-4cad-4a2b9d9f2811"
     }
    
  • Supported profiles

    Profile Name Code LOINC Name and Comments
    Vital Signs Panel 85353-1 Vital signs, weight, height, head circumference, oxygen saturation and BMI panel
    Respiratory Rate 9279-1 Respiratory Rate
    Heart rate 8867-4 Heart rate
    Oxygen saturation 2708-6 Oxygen saturation in Arterial blood
    Body temperature 8310-5 Body temperature
    Body height 8302-2 Body height
    Head circumference 9843-4 Head Occipital-frontal circumference
    Body weight 29463-7 Body weight
    Body mass index 39156-5 Body mass index (BMI)
    Blood pressure systolic and diastolic 85354-9 Blood pressure panel with all children optional
    Systolic blood pressure 8480-6 Systolic blood pressure component
    Diastolic blood pressure 8462-4 Diastolic blood pressure component