Cooking with CQL Q&A: General 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.

$cql operation and test case representation/packaging: Where can I locate the example used in the discussion of $cql operation and test case representation/packaging? (Session 57 - 9/16/21)

• Find the examples used in the discussion of $cql operation and test case representation/packaging on GitHub (https://github.com/WorldHealthOrganization/smart-anc/tree/master/input/tests/library/ANCDT01/charity-with-danger-signs).

CQL vs FHIRv4.0 nested structures: Is the structure of Clinical Quality Language (CQL) in a similar format to the Fast Healthcare Interoperability Resources® (FHIR®) 4.0 nested structure? (Session 53 - 4/22/21)

• Yes. The FHIR model information for CQL follows the same structure as in the FHIR documentation. The code, using FHIR version '4.0.1', tells the translator to bring FHIR into scope.

Additionally, the translator has built-in support for several versions of FHIR and the Quality Data Model (QDM) and now has support for dynamic loading of model information.

Databases in CQL: How do we actually use CQL against a database to generate results? Is this just another way to express measure functions, or does it run somewhere? (Session 25 - 5/31/18)

• CQL is designed to enable the description and distribution of eCQMs, but it also can be a basis for evaluation. There are at least two open source engine implementations of CQL that will actually evaluate the measures and supporting logic.

IG Refresh tooling: In the IG Refresh tooling, when tracking patients that are inpatients in the hospital and have outpatient visits, can a quality measure reference data that would be expected to be present in different systems across both those visits? (Session 56 - 7/29/21)

• Measure specifications do not specify the location of the data or what system the data comes from, although eCQM guidance indicates that the data come from an Electronic Health Record. Current reporting processes typically report from a single data store, though that store may itself be an aggregate such as an HIE. Digital Quality Measures explicitly recognize that data for a measure may come from various sources, including EHRs, Clinical Data Repositories, Health Information Exchanges, and even Personal Health Records and other patient feeds. As an exchange standard, FHIR supports the description of data across all of these servers by using web URLs to reference resources. Note that some expressions used to trace references within FHIR CQL assume that the reference’s logical ID is on the same server., which is a known gap. Approaches are being added to CQL used in a FHIR context to address this issue.