Observation resource implementation guidance
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Observation: Implementation Guidance
Usage
The Observation resource is used to carry a clinical assertion in a CDS context and is created and populated by a CDSS, which will work from clinical assertions to reach decisions.
Due to the nature of triage in unscheduled care, these assertions are often time-bounded and limited, so are appropriate to capture as Observations. The assertions are normally based on input from the patient, captured as QuestionnaireResponses.
A single QuestionnaireResponse can drive a single assertion, or multiple assertions.
Similarly, an assertion may need multiple QuestionnaireResponses to be validated.
Detailed implementation guidance for an Observation resource in the CDS context is given below:
| Name | Cardinality | Type | FHIR Documentation | CDS Implementation Guidance |
|---|---|---|---|---|
identifier |
0..* |
Identifier | Business Identifier for observation | A unique identifier for the Observation. |
basedOn |
0..* |
Reference (Careplan | DeviceRequest | Immunization Recommendation | MedicationRequest | NutritionOrder | ProcedureRequest | ReferralRequest) |
Fulfils plan, proposal or order | |
status |
1..1 |
code | registered | preliminary | final | amended + ObservationStatus (Required). | This will normally be 'final', but may be 'amended' (where a user has amended his/her answers to a question). |
category |
0..* |
CodeableConcept | Classification of type of observation Observation Category Codes (Preferred). | |
code |
1..1 |
CodeableConcept | Type of observation (code/type) LOINC Codes (Example). | Snomed CT code for the Observation. |
subject |
0..1 |
Reference (Patient | Group | Device | Location) |
Who and/or what this is about | This SHOULD be populated with a reference to the Patient resource. |
context |
0..1 |
Reference (Encounter | EpisodeOfCare) |
Healthcare event during which this observation is made | |
effective[x] |
0..1 |
dateTime | Period |
Clinically relevant time/time-period for observation | This SHOULD be populated. |
issued |
0..1 |
instant | Date/Time this was made available | This SHOULD be populated. |
performer |
0..* |
Reference (Practitioner | Organization | Patient | RelatedPerson) |
Who is responsible for the observation | This SHOULD be populated with a reference to the organisation of the service provider which would be taken from the ServiceDefinition. element. |
value[x] |
0..1 |
Quantity | CodeableConcept | string | boolean | Range | Ratio | SampledData | Attachment | time | dateTime | Period | Actual result | This may be of any type, but will often be of type valueBoolean to indicate the presence or absence of the Observation type recorded in the Observation.code element. |
dataAbsentReason |
0..1 |
CodeableConcept | Why the result is missing Observation Value Absent Reason (Extensible) | |
interpretation |
0..1 |
CodeableConcept | High, low, normal, etc. Observation Interpretation Codes (Extensible) | |
comment |
0..1 |
string | Comments about result | |
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 | DeviceMetric) |
(Measurement) Device | |
referenceRange |
0..* |
BackboneElement | Provides guide for interpretation + Must have at least a low or a high or text |
|
referenceRange.low |
0..1 |
SimpleQuantity | Low Range, if relevant | |
referenceRange.high |
0..1 |
SimpleQuantity | High Range, if relevant | |
referenceRange.type |
0..1 |
CodeableConcept | Reference range qualifier Observation Reference Range Meaning Codes (Extensible) | |
referenceRange.appliesTo |
0..* |
CodeableConcept | Reference range population Observation Reference Range Applies To Codes (Example) | |
referenceRange.age |
0..1 |
Range | Applicable age range, if relevant | |
referenceRange.text |
0..1 |
string | Text based reference range in an observation | |
related |
0..* |
BackboneElement | Resource related to this observation | This SHOULD be populated with the QuestionnaireResponse resources which affected the population of this Observation. |
related.type |
0..1 |
code | has-member | derived-from | sequel-to | replaces | qualified-by | interfered-by ObservationRelationshipType (Required) | This should be populated with the value 'derived-from'. |
related.target |
1..1 |
Reference (Observation | Questionnaire Response | Sequence) |
Resource that is related to this one | This SHOULD only be populated with a reference to the QuestionnaireResponse resource. |
component |
0..* |
BackboneElement | Component results | |
component.code |
1..1 |
CodeableConcept | Type of component observation (code/type) LOINC Codes (Example) | Snomed CT code for the Observation. |
component.value[x] |
0..1 |
Quantity | CodeableConcept | string | Range | Ratio | SampledData | Attachment | time | dateTime | Period | Actual component result | |
component.dataAbsentReason |
0..1 |
CodeableConcept | Why the component result is missing Observation Value Absent Reason (Extensible) | |
component.interpretation |
0..1 |
CodeableConcept | High, low, normal, etc. Observation Interpretation Codes (Extensible) | |
component.referenceRange |
0..* |
see referenceRange | Provides guide for interpretation of component result |
