Cooking with CQL Q&A: eCQM Specifications and CQL

Each Q&A has the Cooking with CQL session number and date. For the most current and accurate information, please check the CQL Qs&As for a more recent answer to your question.

Value Set functions in CQL Library v1.5: Are the value set functions described in the Fast Healthcare Interoperability Resources® (FHIR®) Clinical Quality Language (CQL) 1.5 library applicable for the 2023 electronic clinical quality measures (eCQMs) for the Health and Human Services measure reporting programs and when is the release date for the errata to the FHIR CQL 1.5 library? (Session 60 - 1/27/22)

The latest version of CQL is v1.5.1: Mixed Normative/STU, based on Health Level Seven International® FHIR R4. The errata to the FHIR CQL 1.5 library targeted for an early 2022 release will implement the changes. The issue of backwards compatibility of value set references did not impact any of the eCQMs because these aspects were not in use in the current functions.

Profile Authoring in FHIR resources: If a measure developer chooses to use profile authoring, would they be able to use a specific Fast Healthcare Interoperability Resources® (FHIR®) resource in addition to the profile? (Session 60 - 1/27/22)

Measure developers can use profile authoring as well as base FHIR resources directly. Measure developers can use as many of the Implementation Guides (IGs) as needed as the FHIR community has relaxed the Quality Measure IG conformance requirements.

Measure Authoring Development Integrated Environment (MADiE) support profile authoring:Will the Measure Authoring Development Integrated Environment (MADiE) support profile authoring? (Session 60 - 1/27/22)

At this time, there are limits to the MADiE scope. The scope of MADiE will grow over time. The intent is that upon release of the MADiE Minimum Viable Product (MVP), it will support the Quality Improvement -Core Profile informed authoring. CMS is targeting the release of MADiE MVP for late 2022.

Age-based Risk Factors: Can the age-based risk factors example be plugged into the Measure Authoring Tool or tested with Bonnie? The way CQL is structured, the ‘defines’ are listed programmatically. (Session 32 - 2/28/19)

Yes, the way that ‘defines’ are listed in CQL allows them to be forward referenced anywhere in the library. It should be noted that age ranges could be defined as stratifications in the MAT and tested as such within Bonnie.

Flattening in CQL Is flattening part of CQL? (Session 32 - 2/28/19)

Yes. The ‘flatten’ operator takes a list of lists and returns a single list with all the elements of the lists in the input. Because lists may contain lists, CQL provides a flatten operation that can flatten lists of lists:

flatten { { 1, 2, 3 }, { 3, 4, 5 } }

This example returns:

{ 1, 2, 3, 3, 4, 5 }

Note that unlike the union operator, duplicate elements are retained in the result.

Also note that flatten only flattens one level, it is not recursive.

For additional information regarding this topic, please see the 5.6.3. Computing Lists in the Au-thoring Guide (https://cql.hl7.org/2020May/02-authorsguide.html).

Not Equivalent Comparison: For the follow-up HIV visit logic, explain why the not equivalent comparison is not needed and when it could be needed.


define "Followup HIV Visit":
		"Qualifying Encounters" FollowupVisit
			with "Qualifying Encounters" PriorVisit
				such that FollowupVisit.authorDatetime 90 days or more after day of PriorVisit.authorDatetime

(Session 32 - 2/28/19)