HL7 VSD Expression Syntax

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Initial Examples available for download:

1. Assigned Entity Example
   1. The RoleClassAssignedEntity Value Set uses the RoleClass code system. These two value sets are currently used within the HL7 V3 standards and are released in the HL7 MIF file. This example demonstrates two things:
      1. Both RoleClassAssignedEntity and RoleClassContact use an "intensional" definition style to identifying concepts to be included in the expansion set wherein a single code is provided along with a relationship traversal that clarifies that a transitive closure traversal is to be followed to find all codes related to the code provided. This is how "and all descendants" is communicated.
      2. RoleClassAssignedEntity unions together the "code and all descendants" noted above plus a reference to another value set - RoleClassContact.
   2. VSD Example RoleClassContact
   3. VSD Example RoleClassAssignedEntity
2. Chlamydia Condition Example
   1. The Chlamydia value sets described in these examples are actual value sets used in the US electronic quality measure program. The "Grouping" example and the three grouped value sets that make up the grouping: Chlamydia ICD9, Chlamydia ICD10, and Chlamydia SCT, all exist in the US NLM Value Set Authority Center (VSAC). The Chlamydia Union example demonstrates how a single value set using the HL7 Expression could be constructed using enumerated codes from multiple code systems, with each CodeBasedContent set unioned together. Both the Chlamydia Union definition and the Chlamydia Grouping definition generate the same expansion set.
   2. VSD Example Chlamydia Grouping
   3. VSD Example Chlamydia Union
   4. VSD Example Chlamydia ICD9
   5. VSD Example Chlamydia ICD10
   6. VSD Example Chlamydia SCT