specific Concept Representation

Specifies a particular code to be used in the Value Set Expansion Code Set. It may be included on its own or it may define a header code for a set of codes based on specialization relationships with other Concept Representations in the Code System that are to be included in the Value Set Expansion Code Set. Code may be an expression using a Code System that supports the definition of concepts using expression grammar. In these situations it should be noted that the expression must define a single concept and not be an expression that is in essence a query that can represent multiple concepts (i.e., the expression cannot include a subsumption parameter).

This function requires a code anchor. Other types of relationships are handled in sections below for PropertyBasedContent and RelationshipBasedContent, so this is limited to the generalization relationship (i.e., parent/child relationships).

word or set of words to describe the relationship used for traversal to find related codes.

This is the name of relationship between concepts in the Code System that can be used to identify concepts for inclusion in the Value Set Expansion Code Set.

When a Code System has a hierarchy that is not named, then

RelationshipName is to be called “HIERARCHY”.

In a tree of codes of arbitrary depth for a particular relationship, this element identifies whether all codes walking the transitive closure of the specified relationship (“TransitiveClosure”), only those codes with a direct first-level relationship to the selected code (“DirectRelationsOnly”) or only those codes walking the transitive closure of the specified relationship where the code has no outbound relationship of the specified type (“TransitiveClosureLeaves”) should be included.

The 3 defined values are an exhaustive list for this item.

Constrained string (values “TransitiveClosure”, “DirectRelationsOnly” or

“TransitiveClosureLeaves” permitted only)

indicates that the code is included in the content.

The default value is TRUE. Note that if this is set to FALSE and if there are no additional codes to be included, then no codes will be included.

indicates that codes with certain properties in the Code System are part of the Value Set Expansion Code Set.

This optional repeating group of elements indicates that codes having properties in the Code System that match the specified value(s) should be considered part of the content and included in the Value Set Expansion Code Set. Multiple IncludeWithProperty instances are combined using a logical AND. This means that only codes that have properties that match all IncludeWithProperty instances are included in the Value Set Expansion Code Set.

word or set of words to describe the concept property.

This element specifies the moniker of the named concept property in the Code System.

This is the name of the property as published by the Code System publisher.

the value for which the property should be checked.

The value that must be present in the name-value pair associated with the concepts to be included in the expansion code set.

Either Value or Expression must be present. Note that for Code Systems that include properties without values, no value can be specified. In such a case matching on the Name alone would result in inclusion.

string uniquely identifying the relationship being used to filter the content.

The string may be either a unique name or a unique identifier for the relationship type to be used.

This is intended to uniquely identify the kind of relationship to be used in RelationshipBasedContent. The directionality of the relationship should also be clear, i.e., source and target.

an expression that defines the set of Concept Representations that are allowed targets of the named relationship.

If present, this defines the allowed range of concepts for the named relationship.

This may be specified in part as CodeBasedContent, PropertyBasedContent and/or CodeFilterContent. When more than one is used within the expression, the resulting Expansion Code Sets for each collection are unioned together.

COLL (relationship fulfilled by CodeSystemElement)

This element contains a string that specifies the name or short description of the language used to render the expression that is used to filter the codes in CodeFilterContent .

The intent of this is to eventually become a constrained list that describes the syntax used to find the needed strings using a constant name for the syntax. Given that a normative list of the string names is not known, for now an ST data type is used. A few known assumed entries are regexp[^1], regexp_perl, regexp_sxp, regexp_PCRE, POSIX_BRE, POSIX_ERE and POSIX_SRE.

the unique identifier of the referenced Value Set Definition.

This is the “Value Set Identifier” of the Referenced Value Set whose Value Set Expansion Code Set is being included by reference.

uri

While many implementers may populate a Value Set Definition Version as a date, the choice of String as a datatype supports non-date strings that some organizations may want to use to disambiguate the ordinal and sequential nature of Value Set Definition Versions without requiring a full version history. It is also recognized that many implementations will want to use a date as input to a query to retrieve the most current active Value Set Definition at that date. While a date-type version identifier simplifies the approach to meeting that requirement, matching on the version string does not guarantee identifying the correct date-based retrieval. Instead, the best approach would be to compare the requested date provided in this version string to Value Set Definition Version Activity Status Date to determine the most current active Value Set Definition Version as of the requested date.

When no Value Set Definition Version is specified, the Value Set Definition Version is inferred from the context in which the Value Set Definition is used. When the Value Set is referenced in an HL7 binding, then the version that is used is derived from the date/time specified in the STATIC parameter of the binding.

If the Value Set Definition is included as a Value Set Definition Reference Content Defining Element of another Value Set Definition, the version that is used is inherited from the containing Value Set Definition.

If the Value Set Definition is being expanded in the context of a dynamic binding, then the date of the evaluation of the binding (and thus the codes to be used for that conformance evaluation is used as the Value Set Definition Version date/time.

If the Value Set Definition is not part of any binding but is being evaluated separately from its use, then the Value Set Definition Version is either the evaluation date/time or inherited from a containing Value Set Definition.

In essence this means that a Referenced Value Set Definition with no specified version will “inherit” the closest transitively defined version-defining date. This means that a Referenced Value Set Definition with no version ID that is referenced by two different containing Value Set Definitions, each with a different Value Set Definition Version ID, will inherit the Version ID from the containing Value Set Definition (as the closest transitive source of version). This may result in different versions of the same Referenced Value Set Definition being used in each of the containing value sets.

For human display only and may be any of the names that are in the Name element of the Referenced Value Set Definition.

identifies one or more Content Defining Elements such that content from any of them is considered to be part of the Content Defining Element.

This is a recursive inclusion of any sub-type of ContentDefiningElement (see Content Defining Element Types). It is intended to be additive to the set of codes that will be generated in the Value Set Expansion Code Set.

The first instance of CombinedContent MUST be a UnionWithContent. The ‘union’ implies inclusion with any other existing parts of this Content Defining Element specification.

COLL of ContentDefiningElement (see Content Defining Element Types)

identifies Content Expressions that all concepts/codes must also match to be included.

This operation permits a full Content Expression which produces a set of codes which must also be present with the codes that the other content inclusion operations produce (intersection operation).

This may be employed to enable the production of the final set of codes to be populated in the Value Set Expansion Code Set rather than making use of multiple complex sets of Code Based Content inclusions.

identifies content that is explicitly excluded.

Rather than specifying overly complex inclusion criteria, it is sometimes easier to implement a comprehensive inclusion Value Set Definition and then also a simply- defined set of codes that should be removed from the comprehensive Value Set Definition before being populated into the Value Set Expansion Code Set. The Content Expression provides that capability.

group of elements identifying the Code System that applies for this portion of the Content Logical Definition.

Many of the functions in the Content Expression refer to a specific Code System. This group is not needed if the Content Expression for this portion does not refer to any Code System. Note that this is a denormalization, as this information can be ascertained by processing the Content Expression; the information is replicated here for application convenience. There may be at most one of these sections for each Content Expression section and this represents the primary Code System providing any content based upon Code Systems for this value set.

COLL (listed following)

formal registered machine-processable identifier of the Code System.

This is the ID of the Code System rather than its published vernacular name.

This is the same identifier form that is carried in the codeSystem component or property of the HL7 v2.x and ISO 21090 coded datatypes. It should be registered in the HL7 OID Registry.

uri

a dateTime that constrains the associated code system to the single published Code System version that is current as of that dateTime.

When specified, this date constrains the content to the most recent Code System version available at the specified point in time.

It is expected that either the VersionLockedDate or VersionLockedString will be populated in DrawnFromCodeSystem, but not both so there is no conflict. When specified, this element is intended to allow the computable unambiguous identification of a single Code System version. The VersionLockedDate approach should only be used when a VersionLockedString cannot accurately identify the desired version. The level of precision is expected to assure identification of a single unambiguous version. The Content Logical Definition element LockedDate performs a similar, although global, function across the entire CLD in situations where this element is not populated. LockedDate cannot override this element.

a string that constrains the associated Code System to the single published Code System version identified.

This string is under the control of and is published by the Code System authority. When specified, it is expected to unambiguously identify the Code System at a particular published point.

It is expected that either the VersionLockedDate or VersionLockedString will be populated in DrawnFromCodeSystem, but not both so there is no conflict. When specified, this element is intended to allow the computable unambiguous identification of a single Code System version. The level of precision is expected to assure identification of a single unambiguous version. The Content Logical Definition element LockedDate performs a similar, although global, function across the entire CLD in situations where this element is not populated. LockedDate cannot override this element.

human readable signifier for the Code System.

This is a commonly understood name for the Code System and is used for human display purposes.

identifies the partitions of the specified Code System that are included as part of the content.

For those Code Systems that have separable partitions, this identifies a list of partitions that are included with the content.

This is left unpopulated for Code Systems that do not have partitions identified by the Code System author/publisher. This should be a list of partition identifiers that must be used to correctly create a complete Value Set Expansion Code Set. If no partition(s) are listed, then the Value Set Expansion is based on all current partitions. For Value Set Definitions where conformance is a requirement, the Code System uses partitions and all current partitions may not be available to certifying agencies, the specific partitions used MUST be defined. Note that if the CLD is an Intensional definition on a Code System that has multiple partitions and this attribute is not valued, then there may be multiple valid Value Set Expansion Code Sets from the same Value Set Definition. Thus, the recommendation is to generally populate this when defining Value Sets on Code Systems that use partitions. See Code System Partitions and Supplements

identifies a collection of additional concept attributes for the Code System used as part of the Value Set Definition.

Many Code Systems have supplements (see Section Code System Partitions and Supplements) published by the Code System author or by others. The functions defined in the Content Expression are permitted to refer to items that may be defined only within a supplement, as well as items defined within the base Code System, as long as the supplement(s) are listed in this element.

An example of a supplement to the LOINC code system is pCLOCD, which defines additional properties for the concepts in LOINC (it extends the concept model) as well as additional concepts. See Code System Partitions and Supplements.

contains a set of constraints on the DrawnFromCodeSystem or on the Concept Representations in that Code System.

If one of the parameters is present, it affects how the Concept Representations are used in the Value Set Expansion Code Set.

COLL (listed following)

identifies constraints on the Concept Representations to be populated in the Value Set Expansion Code Set when the Code System has multiple Concept Representations available.

If present, the constraint restricts the Concept Representations to be included in the Value Set Expansion Code Set to the specified types (e.g., 2-character vs. 3-character vs. numeric, short names vs. long names, case-sensitive vs. case-insensitive, etc.). It is unused when the Code System specified has only a single Concept Representation available. If multiple Concept Representations exist and no constraints are specified, then all representations are to be included in the Value Set Expansion Code Set.

indicates whether there are no constraints on qualifiers used in the types of Content Expressions.

If true, there are no constraints on qualifiers used in the types of Content Expressions. If false, only those qualifiers found in allowed qualifiers (AllowedQualifiers) with an upper cardinality greater than 0 are permitted.

specifies, through the identified constraints, a subset of allowed concepts based on matching the specified constraints.

This is a group of elements which specify various constraints to the allowed associations (or concept qualifiers) in the base concepts that are selected by the Content Logical Definition.

COLL (listed following)

0..*

word or words to identify the type of relationship from the base concept to the qualifying concept.

This element contains the name of types of relationships that are used for post-coordinated expressions based on relationships in the Code System.