Push for status update for long processing times

[BWorp]

We would like to implement this use-case with CDS Hooks.

• CDS request for starting of a calculation.
• Returning the result of this calculation.

Quite basic, but the calculation takes a long time, typical several minutes. I don't think that sending the response after finishing the calculation is good practice. So the idea is to send a CDS response after basic intake of pre-fetched data. After the calculation is completed, it is then needed to push the status / result.

1. • One way within CDS Hook context I see is mis-use a ad-hock request to the EHR FHIR service to push the status.
2. • Or use the redirect URL from the request to push status.
3. • Or add a proprietary URL in the request for this purpose
4. • Polling using a second CDS request is possible, using a elapsed time indication returned in the CDS Hook reply, is possible but not preferred.

Please advice. Am I missing or misinterpreting something?

Please also refer to this Zulip topic. https://chat.fhir.org/#narrow/stream/cds-hooks/subject/CDS.20async.20reply/near/93110

Thanks in advance, Bart.