Use SDC $populate to pre-fill a FHIR Questionnaire from existing patient data
domain: hl7.org/fhir/uv/sdc · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Identify the target Questionnaire canonical URL and confirm it carries SDC population extensions (item-level population context or launch context extensions)
POST to Questionnaire/$populate with a Parameters resource supplying the subject (Patient reference) and any additional context resources
Receive the returned QuestionnaireResponse with pre-populated answers derived from the patient's FHIR data
Display the pre-populated QuestionnaireResponse to the user, highlighting auto-filled items so they can be reviewed and corrected
On completion, POST the finalized QuestionnaireResponse and optionally invoke $extract to produce structured FHIR resources
Known gotchas
$populate requires the server to have read access to the patient's clinical data; if the Questionnaire references CQL or FHIRPath expressions that query resource types not covered by the session token's scopes, those items will be left blank without error
Population context expressions must match the FHIR version of the server; expressions written for R4 may not evaluate correctly on an R4B or R5 server
The returned QuestionnaireResponse from $populate is transient and not persisted; the client must POST it explicitly after user review
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