The VSAC (Value Set Authority Center) is a repository and authoring tool for public value sets created by external programs. VSAC value sets are lists of codes and corresponding terms, from NLM-hosted standard clinical vocabularies (such as SNOMED CT, RxNorm, LOINC and others), that define clinical concepts to support effective and interoperable health information exchange. The VSAC does not create value set content but allows users to search, author, and/or maintain value sets. The tool provides downloadable access to all official versions of value sets specified by the CMS electronic Clinical Quality Measures (eCQMs). The VSAC is provided by NLM in collaboration with ASTP/ONC and CMS.

Healthcare organizations generate and exchange massive amounts of data that impact clinical, operational, and financial plans. That data is also key to identifying patients who require special care. Given the abundance of data gathered from various sources, consistently grouping this information into clearly defined cohorts can be challenging. Patient condition and treatment data must be accurately gathered to reflect the clinical concepts that define a group, and a high level of specificity is necessary for efforts like clinical trials, quality reporting, and interoperability. Here’s where value sets come into play. The VSAC repository makes searching value sets easy, and it is the source of truth for value sets for CMS's eCQMs.

In the following example, we searched for HL7 C-CDA and "allergy" to find the associated value set.

Click on the OID...

...to see the Metadata and the Description of the value set.