Diagram tab

Owned by Patricia Houghton (Unlicensed)
Last updated: Jan 09, 2023 by María Carolina Berra
2 min read

This tab shows a standardized representation of concept definitions in accordance with SNOMED CT Diagramming Standard. This consists of:

  • the concept whose definition is being shown at the top left
  • connected to a series of one or more relational operators to an expression

Diagram elements

  • Concepts: Concepts are represented by a box containing the concept name.

      The light blue box represents primitive concepts  

     The light purple box with a double-line represents suficiently defined concepts
     
  • Relationships or attributes are represented using a rectangle with rounded ends and a double-line border:


     
  • IS-A  (subtype) relationships are represented with an open-headed arrow:


     
  • Equivalent to:


     
  • Attribute groups are represented with a circle:

     

  • A conjunction is represented with a black “dot” (black filled small circle). It is only
    necessary when two or more attributes are being joined in a diagram. It is optional when
    attaching a single attribute:


     

  • An arrow is used to connect related elements where the connection is unidirectional. Connecting arrows always have an arrow head at one end, and therefore have an explicit direction from one element to another:


     

  • A line is used to connect elements in the diagram where the connection is bidirectional:

     

According to this diagramming standard, a complete concept definition is represented as: