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VSAC Intensional Definition Release Notes: April 11, 2019

Expanded Functionality for Creating VSAC Intensional Definitions


The National Library of Medicine (NLM) Value Set Authority Center (VSAC) is pleased to announce expanded functionality for intensional value sets in the VSAC Authoring Tool. Over the next year VSAC will continue to add more intensional definition functionality, first for RxNorm and subsequently for LOINC value sets.
Do you have examples or use cases? Send them to us!


New Logical Operator: leafOf

You can use this operator to include only the terminal descendant codes of your specified header code, excluding intermediate header (non-billable) codes. You can use the leafOf operator with these code systems: CDT, CPT, ICD10CM and ICD9CM


RxNorm Term Type (TTY) Filtering

You can now constrain your RxNorm value sets to only include certain types of RxNorm terms. Filter RxNorm codes by: IN, PIN, MIN, BN, SCDG, SCDF, SCD, GPCK, SCDC, SBDG, SBDF, SBD, BPCK, SBDC. This initial deployment of RxNorm intensional functionality requires you to manually type the RxNorm Term Types, but in our next deployment we will offer a more user-friendly picklist for you to choose which RxNorm Term Types you need in your value set.


Convert-to-Intensional: Redefine your extensional value set using rule-based logic.

If you can logically define your existing enumerated extensional value set, we encourage you to convert its definition method to “intensional” so that you can create rule-based clauses to more accurately define and efficiently maintain your value set. Your value set will retain the same OID, which is critical when other applications may already be referencing its OID. Learn more...


Later in 2019 we will continue to add intensional functionality for more terminologies, including RxNorm and LOINC®.


You can learn more in our VSAC Support Center: Create an Intensional Value Set


You can contribute to the improvement of this application by sending feedback and ideas to the NLM Support Center. We especially would love to hear from you about specific intensional value sets you want to be able to create in VSAC in the future using RxNorm or LOINC.

Last Reviewed: April 11, 2019