Invoke FHIR Questionnaire $populate (Da Vinci DTR) to pre-fill a questionnaire from EHR data

Verified steps

1. Retrieve the FHIR Questionnaire resource from the payer's or DTR server's endpoint — in the Da Vinci DTR workflow, the Questionnaire is typically obtained as part of the CRD/DTR CDS Hooks response and may include CQL libraries referenced by the Questionnaire items.
2. Invoke the $populate operation (defined in the HL7 SDC or DTR IG — verify the exact operation name and parameters against the current DTR IG) on the Questionnaire, providing the patient context, the encounter context, and optionally the base FHIR server URL where EHR data can be retrieved.
3. The $populate implementation evaluates CQL expressions embedded in Questionnaire item extensions against live EHR data, resolving FHIR queries to retrieve patient demographics, clinical observations, conditions, and other relevant data elements.
4. Receive a pre-filled QuestionnaireResponse resource with answers populated from EHR data; items that could not be resolved from EHR data will be empty and require manual entry by the clinician.
5. Display the QuestionnaireResponse in the DTR SMART app UI, presenting pre-filled answers for clinician review and providing input fields for unanswered items.
6. Upon clinician completion and sign-off, submit the finalized QuestionnaireResponse to the payer or DTR server as specified in the DTR IG, linking it to the prior authorization or coverage determination context.