When using the subscriptions framework, sometimes a server wants to send notifications with queries instead of ids or full resources.

Concrete use cases presented include:

• referrals for services that may be scheduled far into the future (ids of not-yet-created resources are not known)
• complex versions of 'id' notification (e.g., using an operation to fetch a set of resources, etc. - specific case of insurance coverage has been discussed).

This has been discussed both at multiple WGMs and many ad-hoc sessions. A larger document with proposals can be found here.

Based on the conversations, I propose:

• Add a related-query part to the existing R4 notification-event parameters part
• Define a complex extension allowed on SubscriptionStatus.notificationEvent and SubscriptionTopic.notificationShape named http://hl7.org/fhir/uv/subscriptions-backport/StructureDefinition/backport-related-query. The complex extension has two parts:
  • optional (0..1) Coding named queryType
  • required (1..1) string named query.

Once ballot reconciliation is complete on the IG, I will file an appropriate ticket to make matching changes to FHIR R6.