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ActivityDefinition, in the extension
ActivityDefinition.ehealth-referenceRange. These are generic, that is, non-patient specific ranges applicable for the particular activity, say, a measurement of oxygen saturation.ProcedureRequestServiceRequest, in the extension
ProcedureRequestServiceRequest.ehealth-referenceRange. These are patient-specific ranges applicable to the particular activity in the particular CarePlan referencing the ProcedureRequestServiceRequest. A Patient can have multiple CarePlan with multiple ProcedureRequest ServiceRequest and therefore, possibly differing measurement ranges even for the same activity type, say, measurement of oxygen saturation.Observation, in the element
Observation.referenceRange
As is reflected in the cardinality, multiple reference ranges can be defined simultaneously. Upon submission of an Observation, the reference ranges defined in the referenced ProcedureRequest ServiceRequest are copied to the Observation by the service. This way, the set of measurement ranges in effect at the time of submission are captured in the Observation, regardless of how they Patient-specific reference ranges in ProcedureRequest ServiceRequest are maintained and altered.
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