Common CQL Artifacts for FHIR (US-Based)
1.0.0 - Informative 1

Common CQL Artifacts for FHIR (US-Based) - Downloaded Version null See the Directory of published versions

## Query Management

Page standards status: Informative

This topic provides query management guidance for implementers to support the use of CQL within FHIR artifacts such as questionnaires, typically from a DTR application. The functions and guidance provided here facilitate:

- Manage optional server-side parameters
- Check for modifier elements and extensions
- Manage optional _include and _revInclude situations
- Manage _element filtering
- Manage version differences among servers
- Provide simpler functions with typical search parameter filters (e.g. including only final and amended observations)
- Manage extension retrieval for extensions expected to be present (e.g. USCore and CRD extensions)

- Complex element retrieval such as "Cumulative Medication Duration" and "Body Surface Area"

- Authoring
- Patterns
- Libraries
  - USCoreCommon
  - USCoreElements
  - USCoreTests