Observation Resource

Observation is a FHIR resource that is "used to support diagnosis, monitor progress, determine baselines and patterns and even capture demographic characteristics." As such, Observations have a wide range of uses and show up in a wide range of places. FHIR Observations are mapped to OpenMRS Obs objects.

Supported Elements

The following properties are supported by the OpenMRS FHIR Module:

^{Observation.id}
^{Observation.code}
^{Observation.category}
^{Observation.status}
^{Observation.interpretation}
^{Observation.issued}
Observation.encounter
Observation.basedOn
Observation.subject
Observation.value[x]

OpenMRS ↔ FHIR Mapping

OpenMRS Data Model	FHIR Resource Element

OpenMRS Data Model	FHIR Resource Element
^Obs.uuid	^{Observation.id}
^Obs.concept	^{Observation.code}
^Obs.concept	^{Observation.category}
^Obs.status	^{Observation.status}
^{Obs.interpretation}	^{Observation.interpretation}
^{Obs.dateCreated}	^{Observation.issued}
^{Obs.encounter}	^{Observation.encounter}
^Obs.order	^{Observation.basedOn}
^Obs.person	^{Observation.subject}
^Obs.value[x]	^{Observation.value[x]}

¹category is determined by a simple mapping table (fhir_observation_category_map) that maps between the FHIR observation category value-set (if possible) and a particular conceptClass. By default, the following categories will be mapped if the expected versions of them exist in the concept dictionary:

Category	Concept Class

Category	Concept Class
^laboratory	^Test
^procedure	Procedure
^exam	Finding

² value[x] mappings between OMRS and Observation are largely one-to-one where possible. Numeric values are generally mapped to valueQuantity; coded observations are mapped to valueCodeableConcept, etc.

Code System Mapping

The FHIR2 module has a fairly generic system for mapping between OpenMRS concepts and observation codes. The FHIR2 module will send and accept codes from any coding system it knows about. A few of the common ones (note that these should usually be available by default):

URL	Code System

URL	Code System
http://loinc.org	LOINC
http://snomed.info/sct	SNOMED CT
https://openconceptlab.org/orgs/CIEL/sources/CIEL	CIEL

In addition, the FHIR module will send and accept the concept UUID without any system as a reference to that concept. The FHIR module can be instructed to use other systems as well. Mappings between system URLs and the underlying OpenMRS concept sources are maintained in a simple mapping table (fhir_concept_source). Adding a new entry to the table will add a newly supported concept system.

Available RESTful Endpoints

Note: placeholder "{release}" below must be replaced by the FHIR Release - currently "R3" and "R4" are implemented. See more on the FHIR Release support page.

GET

URL	Description

URL	Description
^{/ws/fhir2/{release}/Observation}	Gets all observations
^{/ws/fhir2/{release}/Observation/{uuid}}	Gets a specific observation
^{/ws/fhir2/{release}/Observation?{query}}	Searches for observations matching the provided criteria

Supported Search Parameters

Parameter	Value Type	Description

Parameter	Value Type	Description
^date	date	Searches for observations by the observation date and time
^code	token	Searches for observations with particular codes (concepts)
^category	token	Searches for observations by the observation category
^encounter	reference	Searches the encounter in which this observation was recorded
^subject	reference	Searches for observations by a given patient
^{subject.identifier}	token	Searches for observations by the patient identifier
^{subject.given}	string	Searches for observations based on the patient's given name(s)
^{subject.family}	string	Searches for observations based on the patient's family name
^subject.name	string	Searches for observations based on the patient's full or partial name
^patient	reference	Searches for observations by a given patient
^{patient.identifier}	token	Searches for observations by the patient identifier
^{patient.given}	string	Searches for observations based on the patient's given name(s)
^{patient.family}	string	Searches for observations based on the patient's family name
^patient.name	string	Searches for observations based on the patient's full or partial name
^has-member	reference	Searches for an observation group that contains a given observation
^{has-member.code}	token	Searches for an observation group that contains an observation with the provided code
^{value-concept}	token	Searches for an observation whose value is a concept that matches the provided concept code
^value-date	date	Searches for an observation whose value is a date by the specified date range.
^_id		Searches based on the exact UUID of the person record
^_lastUpdated	date	Searches based on the the dateCreated field for the observation record

¹ See the notes on category mapping above

Supported _includes

Include	Description

Include	Description
^{Observation:encounter}	Includes the encounter for any observations in the result set
^{Observation:patient}	Includes the patient for any observations in the result set
^{Observation:has-member}	Includes the observation group members for any observation group in the result set

Supported _revincludes

Include	Description

Include	Description
^{Observation:has-member}	Includes the observation group observation for any searches that match an observation group memeber
^{DiagnosticReport:result}	Includes the diagnostic report (if any) for which this observation is a result

POST

URL	Description

URL	Description
^{/ws/fhir2/{release}/Observation}	Creates a new observation

DELETE

URL	Description

URL	Description
^{/ws/fhir2/{release}/Observation/{uuid}}	Deletes (voids) the specified observation