Implement US Core 7.0.0 Observation laboratory result search and display
domain: hl7.org/fhir/us/core · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Query the FHIR server using the Observation category search parameter with the value 'laboratory' to retrieve lab results for a patient
Apply _sort and _count parameters to page through large result sets efficiently
Verify each returned Observation conforms to the US Core Laboratory Result Observation profile by checking profile declaration in meta.profile
Extract value[x] with its unit (UCUM-coded) and the LOINC-coded code element for display
Handle both present numeric values and absent values indicated by dataAbsentReason in the rendering layer
Known gotchas
The category code system for laboratory results is a FHIR-defined code system, not SNOMED or LOINC; using the wrong system URI causes the search to return no results
UCUM unit codes are case-sensitive; a unit of 'mg/dL' differs from 'MG/DL' and will fail terminology validation
Servers are not required to support all search parameter combinations; test _sort by date and by status separately before assuming compound sorts work
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