LOINC is a freely available international standard for tests, measurements, and observations. It is a well maintained, version independent code system.
Use of LOINC is governed by the LOINC License: https://loinc.org/license/
This CodeSystem resource describes 'LOINC' independent of any particular version. There are notes about changes for version specific LOINC code system resources.
Note that the following set of codes are defined by the LOINC code systems:
- the main LOINC codes
- the LOINC Answer codes (LA-) and the LOINC Answer list codes (LL-)
- the LOINC Part codes (LP-) in the Multiaxial Hierarchy
- the LOINC Part codes (LP-) for the properties
Note: there are license restrictions on the use of LOINC Part codes
- the LOINC Group codes (LG-)
Note: presently the LOINC Group codes are used to identify these roll-up groups as ValueSets, but are not yet loaded as codes in the CodeSystem
Servers may generate variants of this for the LOINC version(s) and features they support.
File Version: 0.6
-->
<CodeSystemxmlns="http://hl7.org/fhir">
<idvalue="loinc"/>
<!--
This url is unchanged for all versions of LOINC. There can only be one correct Code System resource for each value of the version attribute (at least, only one per server).
-->
<urlvalue="http://loinc.org"/>
<!-- the HL7 v3 OID assigned to LOINC -->
<identifier>
<systemvalue="urn:ietf:rfc:3986"/>
<valuevalue="urn:oid:2.16.840.1.113883.6.1"/>
</identifier>
<!--
If a version is specified:
<versionvalue="2.68"/>
-->
<!--
If a specific version is specified, the name should carry this information (e.g. LOINC_268).
-->
<namevalue="LOINC"/>
<titlevalue="LOINC Code System"/>
<statusvalue="active"/>
<experimentalvalue="false"/>
<publishervalue="Regenstrief Institute, Inc."/>
<contact>
<telecom>
<valuevalue="http://loinc.org"/>
</telecom>
</contact>
<!--
<datevalue=2020-06/>
-->
<descriptionvalue="LOINC is a freely available international standard for tests, measurements, and observations"/>
It's at the discretion of servers whether to present fragments of LOINC hierarchically or not, when using the code system resource. But, if they are hierarchical, the Hierarchy SHALL be based on the is-a relationship that is derived from the LOINC Multiaxial Hierarchy.
-->
<hierarchyMeaningvalue="is-a"/>
<compositionalvalue="false"/><!-- no compositional grammar in LOINC -->
<versionNeededvalue="false"/>
<!--
This canonical definition of LOINC does not include the LOINC content, which is distributed separately for portability.
Servers may choose to include fragments of LOINC for illustration purposes.
-->
<contentvalue="not-present"/>
<!--
<countvalue="65000"/>
If working with a specific version, you could nominate a count of the total number of concepts (including the answers, Hierarchy, etc.). In this canonical definition we do not.
-->
<!--
FILTERS
Generally defined filters for specifying value sets
In LOINC, all the properties can also be used as filters, but they are not defined explicitly as filters.
Parent/child properties are as defined by FHIR. Note that at this time the LOINC code system resource does not support ancestor/descendant relationships.
For illustration purposes, consider this slice of the LOINC Multiaxial Hierarchy when reading the descriptions below:
Microbiology [LP7819-8]
Microorganism [LP14559-6]
Virus [LP14855-8]
Zika virus [LP200137-0]
Zika virus RNA | XXX [LP203271-4]
Zika virus RNA | XXX | Microbiology [LP379670-5]
Zika virus RNA [Presence] in Unspecified specimen by Probe and target amplification method [79190-5]
Language Note: The filters defined here are specified using the default LOINC language - English (US). Requests are meant to be specified and interpreted on the English version. The return can be in a specified language (if supported by the server). But note that not all filters/properties have language translations available.
-->
<filter>
<codevalue="parent"/>
<descriptionvalue="Allows for the selection of a set of codes based on their appearance in the LOINC Multiaxial Hierarchy. Parent selects immediate parent only. For example, the code '79190-5' has the parent 'LP379670-5'"/>
<operatorvalue="="/>
<valuevalue="A Part code"/>
</filter>
<filter>
<codevalue="child"/>
<descriptionvalue="Allows for the selection of a set of codes based on their appearance in the LOINC Multiaxial Hierarchy. Child selects immediate children only. For example, the code 'LP379670-5' has the child '79190-5'. Only LOINC Parts have children; LOINC codes do not have any children because they are leaf nodes."/>
<operatorvalue="="/>
<valuevalue="A comma separated list of Part or LOINC codes"/>
</filter>
<filter>
<codevalue="copyright"/>
<descriptionvalue="Allows for the inclusion or exclusion of LOINC codes that include 3rd party copyright notices. LOINC = only codes with a sole copyright by Regenstrief. 3rdParty = only codes with a 3rd party copyright in addition to the one from Regenstrief"/>
<operatorvalue="="/>
<valuevalue="LOINC | 3rdParty"/>
</filter>
<!--
PROPERTIES
There are 4 kinds of properties that apply to all LOINC codes:
1. FHIR: display, designation; these are not described here since they are inherent in the specification
2. Infrastructural: defined by FHIR, but documented here for the LOINC Multiaxial Hierarchy
3. Primary LOINC properties: defined by the main LOINC table
4. Secondary LOINC properties: defined by the LoincPartLink table
Additionally, there are 2 kinds of properties specific to Document ontology and Radiology codes, respectively:
1. LOINC/RSNA Radiology Playbook properties
2. Document Ontology properties
-->
<!--
Infrastructural properties - inherited from FHIR, but documented here for the LOINC Multiaxial Hierarchy.
<descriptionvalue="A child code in the Multiaxial Hierarchy"/>
<typevalue=""/>
</property>
<!--
Primary LOINC properties.
These apply to the main LOINC codes, but not the Multiaxial Hierarchy, Answer lists, or the Part codes.
Notes:
In the LOINC code system resource, the display element = LONG_COMMON_NAME
Many properties are specified as type "coding", which allows use of LOINC Part codes (LP-) and the display text. LOINC Parts and their associations to LOINC terms are published in the LOINC Part File.
The properties defined here follow the guidance of the LOINC Users' Manual, which states that they should be expressed with the LOINC attributes contained in the LOINC Table. Properties that are not defined in the LOINC Table use FHIR-styled names.
-->
<property>
<codevalue="STATUS"/>
<urivalue="http://loinc.org/property/STATUS"/>
<descriptionvalue="Status of the term. Within LOINC, codes with STATUS=DEPRECATED are considered inactive. Current values: ACTIVE, TRIAL, DISCOURAGED, and DEPRECATED"/>
<typevalue="string"/>
</property>
<property>
<codevalue="COMPONENT"/>
<urivalue="http://loinc.org/property/COMPONENT"/>
<descriptionvalue="First major axis-component or analyte: Analyte Name, Analyte sub-class, Challenge"/>
<typevalue="Coding"/>
</property>
<property>
<codevalue="PROPERTY"/>
<urivalue="http://loinc.org/property/PROPERTY"/>
<descriptionvalue="Second major axis-property observed: Kind of Property (also called kind of quantity)"/>
<descriptionvalue="The LOINC version number in which the record has last changed. For new records, this field contains the same value as the VersionFirstReleased property."/>
<descriptionvalue="This property is populated in collaboration with the HL7 Attachments Work Group as described in the HL7 Attachment Specification: Supplement to Consolidated CDA Templated Guide."/>
<descriptionvalue="A value of Y in this field indicates that this LOINC code can be sent by a payer as part of an HL7 Attachment request for additional information."/>
<descriptionvalue="A name that is more 'clinician-friendly' compared to the current LOINC Short Name, Long Common Name, and Fully Specified Name. It is created algorithmically from the manually crafted display text for each Part and is generally more concise than the Long Common Name."/>
<descriptionvalue="The super system part of the System, if present. The super system represents the source of the specimen when the source is someone or something other than the patient whose chart the result will be stored in. For example, fetus is the super system for measurements done on obstetric ultrasounds, because the fetus is being measured and that measurement is being recorded in the patient's (mother's) chart."/>
<descriptionvalue="The specific gene represented in the analyte"/>
<typevalue="Coding"/>
</property>
<property>
<codevalue="category"/>
<urivalue="http://loinc.org/property/category"/>
<descriptionvalue="A single LOINC term can be assigned one or more categories based on both programmatic and manual tagging. Category properties also utilize LOINC Class Parts."/>
<typevalue="Coding"/>
</property>
<property>
<codevalue="search"/>
<urivalue="http://loinc.org/property/search"/>
<descriptionvalue="Synonyms, fragments, and other Parts that are linked to a term to enable more encompassing search results."/>
<typevalue="Coding"/>
</property>
<!--
LOINC/RSNA Radiology Playbook properties. These apply only to terms in the LOINC/RSNA Radiology Playbook File.
Notes:
Properties are specified as type "coding", which are represented by LOINC Part codes (LP-) and their display names.
The attribute names here use FHIR styled names rather than their original LOINC style names because the original names contain periods.
<descriptionvalue="The Anatomic Location Region Imaged attribute is used in two ways: as a coarse-grained descriptor of the area imaged and a grouper for finding related imaging exams; or, it is used just as a grouper."/>
<descriptionvalue="The Anatomic Location Imaging Focus is a more fine-grained descriptor of the specific target structure of an imaging exam. In many areas, the focus should be a specific organ."/>
<descriptionvalue="Radiology Exams that require laterality to be specified in order to be performed are signified with an Anatomic Location Laterality Presence attribute set to 'True'"/>
<descriptionvalue="Aggregation describes the extent of the imaging performed, whether in quantitative terms (e.g., '3 or more views') or subjective terms (e.g., 'complete')."/>
<descriptionvalue="The Timing/Existence property used in conjunction with pharmaceutical and maneuver properties. It specifies whether or not the imaging occurs in the presence of the administered pharmaceutical or a maneuver designed to test some dynamic aspect of anatomy or physiology ."/>
<descriptionvalue="The Pharmaceutical Substance Given specifies administered contrast agents, radiopharmaceuticals, medications, or other clinically important agents and challenges during the imaging procedure."/>
<descriptionvalue="Subject is intended for use when there is a need to distinguish between the patient associated with an imaging study, and the target of the study."/>
<typevalue="Coding"/>
</property>
<!--
Document Ontology properties.
These apply only to terms in the LOINC Document Ontology File
Notes
Properties are specified as type "coding", which are represented by LOINC Part codes (LP-) and their display names.
The attribute names here use FHIR styled names rather than their original LOINC style names because those contain periods.
<descriptionvalue="Characterizes the training or professional level of the author of the document, but does not break down to specialty or subspecialty."/>
<descriptionvalue="Setting is a modest extension of CMS’s coarse definition of care settings, such as outpatient, hospital, etc. Setting is not equivalent to location, which typically has more locally defined meanings."/>
<descriptionvalue="Characterizes the clinical domain that is the subject of the document. For example, Internal Medicine, Neurology, Physical Therapy, etc."/>
<descriptionvalue="Characterizes the kind of service or activity provided to/for the patient (or other subject of the service) that is described in the document."/>
juan.marchionatto