System Design: The Health Data Hub
Examine the architecture of the National Health Data Office's data hub, including source adapters, patient views, and reporting extracts. Distinguish what acknowledgements, durable ingestion, and data normalisation confirm at each stage of processing. Define release criteria and track completion evidence for each destination to verify that reports meet delivery requirements.
We'll cover the following...
- What the hospital’s acknowledgment promises
- The contracts the three adapters implement
- Where the hub accepts durable responsibility
- What survives normalization of LAB-884
- When a report may enter a patient view or extract
- What proves that LAB-884 became available
- Practice: Designing OP-91’s path independently
Trace report LAB-884 through six processing and delivery milestones:
10:00: Report published by the source.
10:00:01: Report durably stored in the hub's intake system.
10:00:02: Hub sends the hospital an acknowledgement confirming durable receipt.
10:00:04: Report normalised into the hub's internal data model.
10:00:06: Receiving system confirms acceptance of the report.
10:00:08: Report availability confirmed through the authorised consumer's workflow.
The hospital receives a successful intake acknowledgement six seconds before the report becomes available to the care team. The National Health Data Office's ingestion hub must define and track intake acknowledgements and downstream availability separately.
The hub must acknowledge durable receipt so the source can safely hand off delivery responsibility under the agreed contract. Monitoring must distinguish successful intake from confirmed downstream availability.
What the hospital’s acknowledgment promises
An acknowledgement confirms that the receiver met the agreed acceptance conditions. Downstream availability requires separate verification.
In HL7 v2.5.1 original acknowledgement mode, transport success alone does not confirm application-level acceptance. The standard allows acknowledgement after a message enters an input queue with database-level integrity, provided the receiver accepts responsibility for subsequent processing. It does not specify the receiver's downstream workflow or architecture.
For this case, define the positive hospital acknowledgement as: "The hub accepted the message after completing the agreed validation checks and durably recorded it for recoverable processing."
Verify this acknowledgement contract against the applicable HL7 version, local message profile, acknowledgement mode, and receiver processing boundary. This acknowledgement does not confirm downstream delivery, consumer access, or clinical review.
Keep the scoped workflows separate:
Hospital care access: Proposed target of five minutes from source publication to availability in the authorised receiving workflow.
Clinic care access: Separate workflow with a proposed fifteen-minute target from source ...