A SNOMED CT Expression Constraint is a computable rule that can be applied to an instance of a SNOMED CT expression to test whether it complies with rules that may relate to its meaning and/or compositional structure. LRA Release 1.0 supports the following two types of expression constraint:

• Semantic - a type of expression constraint which limits the possible meanings that can be expressed by a field.
• Literal - a type of expression constraint which constrains the ways in which an expression may be constructed to represent a given meaning.

Default expression constraints (of either type) are constraints which are bound to reference model classes and which are therefore inherited by default by conforming domain model classes. An expression constraint bound to a domain model may be further refined but must always conform to the default expression constraint from which it derives. SNOMED CT Expression Constraints are described as Terminology Expression Constraints in NPFIT-FNT-TO-DPM-0911.12 LRA Artefacts Overview. The SNOMED CT-based expression constraints and example expressions reference content published in the April 2011 UK Edition of SNOMED CT. In addition, a small number of expression constraints and example expressions reference draft content included for purposes of LRA testing. For practical and safety reasons this draft content is not included in the standard UK Edition of SNOMED CT, and instead is represented using a non-authentic SNOMED CT identifier (of the form LRA_SCT_nnnnn where n is an integer) and a preferred term. A list of all non-authentic SNOMED CT content included in the LRA testing materials can be found here.

Semantic

• Default semantic expression constraint for activated clotting time

• Default semantic expression constraint for a Procedure Activity

• Default semantic expression constraint for body height measurement

• Default semantic expression constraint for BodyWeightObservation PROPERTY_OBSERVATION_ELEMENT

• Default semantic expression constraint forcapillary refill time

• Default semantic expression constraint for FINDING_OBSERVATION_ELEMENT

• Default semantic expression constraint for GENERAL_ACTIVITY_ELEMENT

• Default semantic expression constraint for Generic Problems and Issues FINDING_OBSERVATION_ELEMENT

• Default semantic expression constraint for INVESTIGATION_ACTIVITY_ELEMENT

• Default semantic expression constraint for Lives Alone Finding ELEMENT

• Default semantic expression constraint for MATERIAL_ACTIVITY_ELEMENT

• Default semantic expression constraint for MATERIAL_ENTITY_ELEMENT

• Default semantic expression constraint for oxygen saturation

• Default semantic expression constraint for Problems and Issues

• Default semantic expression constraint for PROPERTY_OBSERVATION_ELEMENT

• Default semantic expression constraint for Property Observation

• Default semantic expression constraint for RECORD_ARTEFACT_ELEMENT

• Default semantic expression constraint for RELATED_PARTY relationship attribute

• Default semantic expression constraint for treatment device

• Semantic expression constraint for AdmissionEvent GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for Allergies or Adeverse Reaction Event

• Semantic expression constraint for Allergies or Adeverse Reaction Propensity

• Semantic expression constraint for Allergy or Adeverse Reaction Propensity FINDING_OBSERVATION_ELEMENT

• Semantic expression constraint for AllergyOrAdverseReactionEvent FINDING_OBSERVATION_ELEMENT

• Semantic expression constraint for BloodPressureMeasurement INVESTIGATION_ACTIVITY_ELEMENT

• Semantic expression constraint for BloodPressureObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for BloodUreaObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for COMPOSITION

• Semantic expression constraint for ConcernExpectationOrWish FINDING_OBSERVATION_ELEMENT

• Semantic expression constraint for Current Diagnosis At Discharge

• Semantic expression constraint for Current Medication Reconciliation Status using temporary, unpublished SCT Identifiers specific to the LRA project

• Semantic expression constraint for DeathEvent FINDING_OBSERVATION_ELEMENT

• Semantic expression constraint for DiagnosisName FINDING_OBSERVATION_ELEMENT

• Semantic expression constraint for Diagnosis Status using temporary, unpublished SCT Identifiers specific to the LRA project

• Semantic expression constraint for DiagnosisTag RECORD_ARTEFACT_ELEMENT using temporary, unpublished SCT Identifiers specific to the LRA project

• Semantic expression constraint for DiastolicPressureObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for DischargeEvent

• Semantic expression constraint for EstimatedBodyWaterCompositionObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for FluidIntakeVolumeObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for GenericAdmissionEvent GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericAdmissionProspect GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericAssessment INVESTIGATION_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericDischargeEvent GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericDischargeProspect GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericDiscussion GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericSpecimen MATERIAL_ENTITY_ELEMENT

• Semantic expression constraint for GenericTransferEvent GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericTransferProspect GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for GenericTreatment GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for HaemodialysisAccessFlowRateObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for HaemodialysisUrineVolumeMeasurement INVESTIGATION_ACTIVITY_ELEMENT

• Semantic expression constraint for HaemodialysisUrineVolumeMeasurement INVESTIGATION_ACTIVITY_ELEMENT

• Semantic expression constraint for HaemodialysysAccessRecirculationObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for Kt/V PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for Medication Activity

• Semantic expression constraint for NormalisedProteinCatabolicRate PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for PrintedMaterial MATERIAL_ENTITY_ELEMENT

• Semantic expression constraint for product or substance

• Semantic expression constraint for ProvisionOfAdviceOrInformation GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for PulseRateObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for SpecimenCollection GENERAL_ACTIVITY_ELEMENT

• Semantic expression constraint for standing height

• Semantic expression constraint for Stopped Medication Reconciliation Status using temporary, unpublished SCT Identifiers specific to the LRA project

• Semantic expression constraint for subject of care

• Semantic expression constraint for SystolicPressureObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for TemperatureMeasurement INVESTIGATION_ACTIVITY_ELEMENT

• Semantic expression constraint for TemperatureObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for treatment device maintenance

• Semantic expression constraint for UreaDistributionVolumeObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for UreaReductionRatioObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for UrineCreatinineObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for UrineUreaObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for UrineVolumeObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for WashbackVolumeObservation PROPERTY_OBSERVATION_ELEMENT

• Semantic expression constraint for weight measurement

Literal

• Literal expression constraint for AllergyOrAdeverseReactionPropensity FINDING_OBSERVATION_ELEMENT

• Literal expression constraint for AllergyOrAdverseReactionEvent FINDING_OBSERVATION_ELEMENT