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