Patient referrals are closed-loop workflows, not single messages
A referral starts as clinical intent, but it only becomes safe care when another organization can receive it, accept it, act on it, and return a result or status back to the requester.
Radiology is a useful reference architecture because the loop is visible: order creation, triage, scheduling, modality execution, reporting, and result delivery each happen in different operational contexts. The same architectural lesson applies to specialist, therapy, and community referrals.
Closed-loop referral architecture
Loading diagram...
The authored diagram above is intentionally simplified for first-pass learning. This official IHE figure is worth pairing with it because it shows the formal actor boundaries underneath order placement, scheduling, acquisition, archive, evidence creation, and display.
Why this track uses radiology as the worked example
Radiology exposes the operational edges clearly, but the same state-management pattern applies to specialist referrals, therapy pathways, and cross-organizational care coordination.
ServiceRequest - FHIR v4.0.1
Official HL7 resource definition for service orders and referrals, including the workflow relationship to DiagnosticReport and Task.
Read the ServiceRequest specificationIHE Radiology Scheduled Workflow profile
IHE reference describing continuity and integrity of imaging workflow data across ordering, scheduling, acquisition, and reporting steps.
Read the Scheduled Workflow profileClosed-loop care only works when the referral has explicit states
A real referral platform needs more than an inbox and an audit trail. It needs a shared state vocabulary that tells operators whether the request is merely received, clinically accepted, scheduled, in progress, completed, or unable to complete.
That is what lets teams separate acceptance from booking, booking from performance, and performance from final closure. Without explicit states, organizations end up treating handoffs as complete just because a message was transmitted.
Representative referral state machine
Loading diagram...
Contained HISO 10011.1 referral business-process standard
Contained legacy referral-process standard defining a concrete business-state and event model for the referral lifecycle.
Read HISO 10011.1 (contained standard)Contained HISO 10011.3 referral implementation guide
Contained legacy implementation guide that remains useful for mapping referral business events such as receive, validate, assign, triage, and discharge into system behavior.
Read HISO 10011.3 (contained guide)A safe referral loop depends on explicit workflow artifacts
The architectural mistake to avoid is pretending one payload contains every state you need forever. Referral systems usually combine an order artifact, one or more execution artifacts, and one or more outcome artifacts because different systems are authoritative at different stages.
Representative referral order payload
Example FHIR ServiceRequest showing the minimum information needed to route and action a diagnostic referral safely.
Click on an annotation to highlight it in the JSON
Core referral artifacts and who usually owns them
| Artifact | Typical owner | Why it matters |
|---|---|---|
| Referral order or ServiceRequest | Referring EHR or order placer | Carries clinical intent, requested service, and requester identity. |
| Operational task, booking record, or accession | Receiving referral system or departmental workflow | Tracks work acceptance, readiness, scheduling, and execution. |
| DiagnosticReport, ORU, or discharge status | Servicing organization | Closes the loop with results, completion, or inability to perform. |
Task - FHIR v4.0.1
Official workflow resource for tracking operational work that the receiving organization needs to perform around the referral.
Read the Task resourceDiagnosticReport - FHIR v4.0.1
Official result resource used when the servicing organization closes the loop with reportable findings and linked observations.
Read the DiagnosticReport resourceKnowledge Check
Test your understanding with this quiz. You need to answer all questions correctly to mark this section as complete.