Query documents using IHE MHD ITI-67 Find Document References and retrieve content via ITI-68

Steps

1. Authenticate to the Document Responder actor's FHIR endpoint using the appropriate mechanism (OAuth2/SMART or a configured trust relationship per the deployment's security model).
2. Execute ITI-67 by issuing a FHIR search on DocumentReference with required query parameters: at minimum, patient (or patient.identifier), and optionally status, type, category, period, or setting — verify supported parameters against the Document Responder's CapabilityStatement.
3. Evaluate the returned searchset Bundle of DocumentReference resources; each entry describes a document including metadata (type, date, author, content type) and a URL in content.attachment.url pointing to the retrievable document.
4. Execute ITI-68 by issuing an HTTP GET to the URL provided in DocumentReference.content.attachment.url to retrieve the actual document content; the content may be a Binary resource, a CDA XML document, PDF, or FHIR document Bundle depending on the content type.
5. Handle content.attachment.hash and content.attachment.size values if provided to verify document integrity after retrieval.
6. Page through ITI-67 search results using Bundle pagination links if the patient has many documents.