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Logical Observation Identifiers Names and Codes (LOINC) is a standardized coding system for laboratory and clinical tests, procedures, observations, surveys, and corresponding results.
All LOINC source information is obtained from the following:
1. LOINC Website that is supported by the Regenstrief Institute:
2. The National Library of Medicine (NLM) Website:
Source Concept Type | Standard Concept |
---|---|
LOINC Observations and Measurements | Standard |
LOINC Answers | Standard |
LOINC Hierarchy | Classification |
LOINC Classes | Classification |
LOINC Categories | Classification |
LOINC Groups | Classification |
LOINC Concepts are located in such domains as “Observation”, “Measurement”, or “Meas Value”.
Previously all concepts with a LOINC property of “classtype” with values “1” and “2” were considered to be Measurements. However, an initial analysis of such extended LOINC properties as “property”, system”, “scale_type”, “class”, “method_typ”, “definitiondescription” and “survey_quest_text” revealed that the LOINC domain distribution can be more accurate if used the combinations of LOINC properties. In turn, the Concept Class definition is interconnected with a defined Domain.
So, they were assigned pursuant to the following criteria:
Source | Depending on | Domain |
---|---|---|
LOINC | CLASSTYPE=1 or 2 | Measurement |
CLASSTYPE=3 or 4 | Observation | |
LOINC Hierarchy | Concept_code>'LP76352-1' | Observation |
Concept_code>='LP76352-1' | Measurement | |
LOINC Class | Manual | Observation or Measurement |
LOINC Answer | Meas Value |
Relationships are defined within LOINC and between LOINC and CPT, and LOINC and SNOMED:
A purpose of Internal LOINC relationships is to build a LOINC Hierarchy, which makes it easier to sort and browse the database.
Relationship | From | To |
---|---|---|
Is a | Descendant LOINC Class | Ancestor LOINC Class |
Is a | LOINC Group | LOINC Group Category |
Is a | LOINC Measurement or Observation | LOINC Class |
Is a | LOINC Measurement or Observation | LOINC Group |
Is a | Descendant LOINC Measurement or Observation | Ancestor LOINC Measurement or Observation |
Panel contains | LOINC Panel | LOINC Measurement or Observation |
Has Answer | LOINC Question | LOINC Answer |
Has type of service | LOINC Measurement or Observation | LOINC concept indicating a Type of Service (Document Ontology) |
Has subject matter | LOINC Measurement or Observation | LOINC concept indicating a Subject Matter Domain (Document Ontology) |
Has role | LOINC Measurement or Observation | LOINC concept indicating a Role (Document Ontology) |
Has setting | LOINC Measurement or Observation | LOINC concept indicating a Setting (Document Ontology) |
Has kind | LOINC Measurement or Observation | LOINC concept indicating a Kind of Document (Document Ontology) |
Concept replaced by | Updated LOINC concept | New LOINC concept |
Reverse Relationship | From | To |
---|---|---|
Subsumes | Ancestor LOINC Class | Descendant LOINC Class |
Subsumes | LOINC Group Category | LOINC Group |
Subsumes | LOINC Class | LOINC Measurement or Observation |
Subsumes | LOINC Group | LOINC Measurement or Observation |
Subsumes | Ancestor LOINC Measurement or Observation | Descendant LOINC Measurement or Observation |
Contained in panel | LOINC Measurement or Observation | LOINC Panel |
Answer of | LOINC Answer | LOINC Question |
Type of service of | LOINC concept indicating a Type of Service (Document Ontology) | LOINC Measurement or Observation |
Subject matter of | LOINC concept indicating a Subject Matter Domain (Document Ontology) | LOINC Measurement or Observation |
Role of | LOINC concepts indicating a Role (Document Ontology) | LOINC Measurement or Observation |
Setting of | LOINC concepts indicating a Setting (Document Ontology) | LOINC Measurement or Observation |
Kind of | LOINC concepts indicating Kinds of Document (Document Ontology) | LOINC Measurement or Observation |
Concept replaces | New LOINC concept | Updated LOINC concept |
These relationships are defined as “LOINC - SNOMED eq” between “LOINC Hierarchy” Concepts and SNOMED Concepts representing the entity that is measured. Note that only a small fraction (1%) is currently mapped. Also, note that some of the mappings seem to confuse the testing for drugs with the drugs themselves.
These relationships are defined as “LOINC - CPT4 eq” between LOINC Lab Test Concepts and SNOMED Concepts. Note that only a small fraction (2%) is mapped.
All internal “Is a” and “Panel contains” relationships participate in the creation of the CONCEPT_ANCESTOR table, creating an internal hierarchy within LOINC not connected to the larger Measurement or Observation Domain space.