The design of the ordered reference set supports three overall purposes:
- To specify a sequential order of a subset of components
- To specify prioritized groups within a subset of components
- To define alternative hierarchies of components
Ordered reference set can also be used to create a simple ordered list of components, i.e. a list that do not include any nesting, or groups. For ordered lists that do not require grouping or hierarchical arrangement the value of linkedToId should be the digit zero (0), as this attribute becomes irrelevant.
This type of ordered reference set can for example be used to prioritize the sort order of the descriptions with identical terms when they are displayed. It can also be used to specify the order of descriptions displayed in a simple pick list.
Figure 1: Ordered reference set with no groups
Prioritization is similar to order but multiple components may have the same rank. In this case the value of the order attribute specify a priority order for a group of components.
Figure 2: Ordered reference set with prioritized groups.
The diagram below Illustrates how the three attributes referencedComponentId, order and linkedToId are used to create an alternative hierarchical order of some of the concepts from the subtype hierarchy.
Figure 3: Ordered reference set example.
Reference Set Specific Attributes
Specific reference set attributes used to build an alternative hierarchical view of SNOMED CT
The identifier of a SNOMED CT component that is included in the ordered list of alternative hierarchy.
Specifies the sort order of the list. The list is ordered by applying an ascending sort of the order value.
The identifier of a SNOMED CT component that acts as a grouper or hierarchy node, collecting together a subgroup from within the list.