LOINC Release Notes

This section last updated: 2023-02-22 (3 months ago)

Version 2.74, February 2023

Table of contents:

• LOINC table core
• LOINC table
• Answer lists
• Change snapshot
• Consumer names
• Document ontology
• Document ontology OWL
• Groups
• Imaging document codes
• Linguistic variants
• LOINC/IEEE medical device code mapping table
• LOINC/RSNA radiology playbook
• LOINC Universal lab orders value set
• Component Hierarchy By System
• Panels and forms
• Parts
• Updates

LOINC table core

There were no structural changes to the core table in this release, and no future changes to announce at this time. See the Readme included in the LOINC Table Core download file for information about its current file structure.

See the LOINC table notes below for information on content updates included in this release.

LOINC table

Numbers

New terms and totals by type

Totals by Status

Term Status changes

Edits by change type

New content highlights

SARS-CoV-2/COVID-19

During this release cycle we continued to prioritize creating LOINC terms and other resources related to SARS-CoV-2/COVID-19 testing, clinical care, documentation, and reporting. We continued to work closely with the CDC, FDA, APHL, laboratories, IVD manufacturers, and other stakeholders to create LOINC content for SARS-CoV-2 laboratory tests.

LOINC terms related to SARS-CoV-2/COVID-19 testing, ask-at-order entry questions, case reporting, clinical documentation, and surveys can be found on a dedicated webpage that supports downloads of filtered subsets of these terms (https://loinc.org/sars-cov-2-and-covid-19/). This page includes both released and pre-release terms and is updated as soon as new terms or term edits are made.

A separate page provides guidance for choosing LOINCs for SARS-CoV-2 testing and general FAQs (https://loinc.org/sars-coronavirus-2).

New Rankings up to 20,000 to replace the former Top2000

We have added refreshed rankings of the 20,000 most commonly used LOINC codes in the U.S. Check out these new rankings in the COMMON_TEST_RANK field in the Loinc.csv file, or the Rank column in SearchLOINC.

The new rankings replace the previous "Top 2000" lab codes, which were out of date and included only lab. The new ranks encompass clinical as well.

Please read further details about the new rankings on the LOINC website.

Mapping of LOINC Parts to External Ontologies

The Component Parts of a LOINC term can be linked to codes from external coding systems. The external mappings serve to provide links from LOINC detail pages to external information sources, and are also provided in the Partfile directory in the distribution in a file named PartRelatedCodeMapping.csv, which can be used in various ways to organize LOINC codes by external axes as needed. Such linkages in the laboratory domain include mappings to ChEBI (Chemicals of Biologic Interest) and NCBI’s PubChem for chemicals, NCBI’s Gene for genes, NCBI’s ClinVar for genetic variants, and NCBI’s Taxonomy for microorganisms. Clinical linkages include NLM’s RxNorm for drug ingredients and RSNA’s RadLex Clinical Terms for radiology concepts. There is also a set of LOINC Parts mapped to SNOMED CT (SCT) concepts.

For the current LOINC release 2.74, hundreds of additional mappings were created between LOINC Component Parts and ChEBI, NCBI Taxonomy, Genes and ClinVar databases, as well as FDA UNII codes.

Lyme disease

Modified two-tiered testing for the serological diagnosis of Lyme disease were created during this release cycle to support the screening with enzyme immunoassays or EIAs and confirm equivocal and positives with EIAs. See 62341-3 for the standard two-tiered testing algorithm.

We will continue to work closely with the CDC, FDA, APHL, laboratories, IVD manufacturers, and other stakeholders to create LOINC content for Lyme Disease laboratory tests.

New laboratory content highlights

• Over 140 new microbiology terms, with one related to the pandemic virus, SARS-CoV-2 (COVID-19). Many others were created to support specialized microorganism testing by the CDC.
• 3 new microbiology terms related to supporting Monkeypox virus testing, including clade and lineage.
• 25 new microbiology terms related to veterinary medicine.
• 29 new chemistry terms, including terms related to neurofilament light chains, ligands, bacterial versus viral infection likelihood, and others.
• Over 40 new serology terms, including terms related to calculating the risk of solitary lung nodule malignancy.
• 48 new blood bank terms for the measurement of various antibodies and antigens.
• 40 new drug/toxicology terms for testing performed on various specimens.
• Over 30 new molecular genetic tests, including multigene studies for preimplantation, lung cancer, genetic disease analysis, and various other conditions.

New clinical content highlights

• 2 new cardiac procedure terms, including cardioversion and cardiac device monitoring reports. Other cardiac terms were created to support congenital disease monitoring.
• 6 new clinical risk terms, including CHAMPS pediatric fall risk assessment and the Schmid fall risk assessment.
• 60 new document ontology terms, including various history and physical notes, surgical operation notes, consultation notes, conference notes, and others.

New survey content

• 1 new panel for the Centers for Medicare and Medicaid (CMS) assessment: MDS v3.0 - RAI v1.18.11 - Nursing home comprehensive (NC) item set (this new panel should be used for performance between October 1, 2023 and September 30, 2024.)
  • The Minimum Data Set (MDS) is part of a federally mandated process for clinical assessment of all residents in Medicare or Medicaid certified nursing homes. This process entails a comprehensive, standardized assessment of each resident's functional capabilities and health needs.

Term edit highlights

Changes based on internal review or as part of an ongoing project

• Harmonized the naming model for terms representing studies
• For studies detecting neutralizing antibodies, updated "Ab" to "Ab.Neut" in the Component
• Updated Thermoactinomyces sacchari to Laceyella sacchari in the Component
• Removed the Method from several terms that represent generic concepts to allow broader use
• Updated terms from TRIAL to ACTIVE status

Changes based on community input

• Corrected several minor typos in Components and display names
• Updated the Order and/or Observation value to Both in the Order/Observation field for several terms to allow for broader use
• Updated the Required (R) value to Optional (O) in the Conditionality field for several panels and/or added additional children to allow for broader use

Source Organization

LOINC version 2.74 contains copyrighted content that is used with permission from the organizations documented in the SourceOrganization table. Users of this content must follow the copyright holders' terms of use.

Change to the LOINC Table structure in this release

Field Name: UnitsAndRange

Formal Definition: Units of measure (expressed using UCUM units) and normal ranges for physical quantities and survey scores. Intended as tailorable starter sets for applications that use LOINC forms as a way to capture data. Units are separated from normal ranges by a colon (:) and sets of unit:normal range pairs are separated by a semi-colon (;). Syntax for the normal range includes square brackets, which mean that the number adjacent to the bracket is included, and parentheses, which means that the number itself is not included. For example, [2,4] means “two to four”, while [2,4) means “two to less than four” and (2,4) means “between two and four but does not include two and four”.

Action: DELETE

Discussion: This field is sparsely populated and has not been maintained over time, primarily because reference ranges can vary between laboratories based on population characteristics and other factors. This field was emptied in the June 2021 release and has been August 2022 release.

Field Name: SUBMITTED_UNITS

Formal Definition: Units as received from person who requested this LOINC term

Action: DELETE

Discussion: For the last several years we have included the submitted units in the EXAMPLE_UNITS field, and the SUBMITTED_UNITS field has not been consistently populated since 2012. This field was emptied in the June 2021 release and has been deleted in the August 2022 release.

Field Name: CDISC_COMMON_TESTS

Formal Definition: "Y" in this field means that the term is a part of a subset of terms used by CDISC clinical trials.

Action: DELETE

Discussion: The CDISC_COMMON_TESTS field has not been maintained over time and has not been populated for any LOINC terms created since 2011. This field was emptied in the June 2021 release and has been deleted in the August 2022 release.

Field Name: EXAMPLE_SI_UCUM_UNITS

Formal Definition: The Unified Code for Units of Measure (UCUM) is a code system intended to include all units of measures being contemporarily used in international science, engineering, and business. This field contains example units of measures for this term expressed as SI UCUM units.

Action: DELETE

Discussion: The UCUM standard contains both SI and non-SI units, and a single unit is either one or the other. A single LOINC Property will match with a specific set of UCUM units, in some cases SI and in some cases non-SI. These units are already provided in the EXAMPLE_UCUM_UNITS field and do not require a separate field. The EXAMPLE_SI_UCUM_UNITS field was emptied in the June 2021 release and has been deleted in the August 2022 release.

Changes to the LOINC Table structure planned for August 2023

Field Name: COMMON_SI_TEST_RANK

Formal Definition: Corresponding SI terms for 2000 common tests performed by laboratories in USA.

Action: DELETE

Discussion: In this release, the old Top 2000 common ranks were updated with a new set of values. These new rankings do not differentiate between SI and mass based measurement making this field obsolete. For the 2.73 release all records in this field have been set to a value of 0. This field will be deleted in the August 2023 release of LOINC

See Appendix A in the LOINC Users' Guide for the current LOINC table structure.

Answer Lists

See the ReadMe included in the Answer File folder for information about its current file structure.

This release contains all of the answer lists associated with any LOINC term published in the current release. There have been no changes other than the addition of new content since the last release.

Change Snapshot

See the ReadMe included in the Change Snapshot folder for information about its current file structure.

The LoincChangeSnapshot file contains all terms that had a change in Status between LOINC version 2.73 and version 2.74, such as from TRIAL to ACTIVE. It does not contain terms that were newly added in 2.74. In the future, this file will likely contain other types of term changes in addition to Status changes.

The PartChangeSnapshot file contains all of the Parts that had a change in Status between LOINC version 2.73 and version 2.74, such as from ACTIVE to DEPRECATED or ACTIVE to INACTIVE (see ReadMe for Status definitions). In the future, this file may contain other types of Part changes in addition to Status changes.

Consumer Names - Alpha

See the ReadMe included in the Consumer Name folder for information about its current file structure.

This release of the Consumer names file remains at Alpha pre-production status. It contains Consumer names for all Type 1 (Laboratory) and a subset of Type 2 (Clinical) terms in LOINC. The Consumer Names are created algorithmically based on the set of primary rules documented in the associated ReadMe notes.

Consumer Names are intended for downstream display only and are not intended to be used at any point in the clinical workflow, or for the purpose of mapping local terms to LOINC. Their use case includes consumer-facing health and wellness applications that use LOINC to encode the underlying data.

We welcome user feedback about these names.

Document Ontology

See the ReadMe included in the Document Ontology folder for information about its current file structure.

Document ontology OWL - Alpha

See the ReadMe included in the Document Ontology OWL folder for information about its current file structure.

The Document Ontology OWL file released with LOINC version 2.74 includes all the changes and additions to LOINC documents and document ontology values in a format that allows navigation of document axis hierarchies and exchange as a formal ontology. It continues at Alpha status, meaning that it is part of a testing process, and the LOINC team continues to welcome comments regarding its usability and content.

Groups - Beta

See the ReadMe included in the Group File folder for information about its current file structure.

This release of the Group File remains at Beta pre-production status. We received no significant public comments about its contents, structure, or utility that we would have used as the basis for incrementing its maturity level or conceptualization. If you are using this file and have feedback (good or bad), please contact us.

Imaging Document Codes

See the ReadMe included in the Imaging Document folder for information about its current file structure and query used to generate the set of LOINC codes.‌

There have been no changes other than the addition of new content since the last release.

Linguistic Variants

See the ReadMe included in the Linguistic Variants folder for information about its current file structure.

Updated linguistic variants are generally based on the previous release version (i.e., LOINC version 2.73 is translated for inclusion in the 2.74 release).

Updated content for the LOINC 2.74 release has been provided by the translation for the following linguistic variants:

· de_DE German (GERMANY)

· el_GR Greek (GREECE)

· es_ES Spanish (SPAIN)

· et_EE Estonian (ESTONIA)

· fr_BE French (BELGIUM)

· fr_CA French (CANADA)

· it_IT Italian (ITALY)

· nl_NL Dutch (NETHERLANDS)

· pl_PL Polish (POLAND)

· ru_RU Russian (RUSSIAN FEDERATION)

· tr_TR Turkish (TURKEY)

· uk_UA Ukraine (UKRAINIAN)

· zh_CN Chinese (CHINA)

The table below shows the LOINC version when each linguistic variant included in this release was last updated.

Please note that some term translations are based on the translation of Parts. For such translations, even if no additional Part translations were provided by the producer, the number of translated terms may vary from release to release because new LOINC terms using previously translated Parts will also be included, and old LOINC terms that have been updated to use untranslated Parts will be excluded.

LOINC IEEE Medical Device Code Mapping Table

See the ReadMe included in the LOINC IEEE Medical Device Code Mapping Table folder for information about its current file structure.

There have been no changes to the structure or contents of this file since the LOINC 2.67 release in December 2019.

LOINC RSNA Radiology Playbook

See the ReadMe included in the LOINC RSNA Radiology Playbook folder for information about its current file structure.

There have been no changes other than the addition of new content since the last release.

The mappings to and content from the RSNA Playbook are based on version 2.4 of that terminology, and Radiology Part mappings are based on RadLex version 4.1 and pre-release 4.2.

We are still seeking feedback on the usefulness of the PartSequenceOrder field from anybody who is utilizing this file to help inform our future efforts, e.g., whether we should remove this field.

Known issues:

Parsing issue for terms with multiple Aggregation or View type values in which one or more values is not being assigned the correct PartSequenceOrder value. We plan to address the parsing procedure in a future release if necessary, depending on whether users find this field useful (see request for feedback above).

A few outstanding cases for LOINC Radiology Parts without mappings to RadLex RIDs exists. We plan to review these with RSNA and add mappings, as appropriate, in a future release.

Terms with XXX (meaning Unspecified) as the Region Imaged without an Imaging focus do not have an Anatomy attribute (Region imaged or Imaging focus) represented in the file. The LOINC/RSNA Committee is reviewing the representation of XXX without a specified imaging focus in the LOINC/RSNA model to determine how the Anatomy should be represented.

LOINC Universal Lab Orders Value Set

See the ReadMe included in the LOINC Universal Lab Orders Value Set folder for information about its current file structure.

There have been no changes to this file since the last release.

Component Hierarchy By System

The Component Hierarchy By System (formerly known as Multiaxial Hierarchy) file provides a way to organize LOINC codes based on multiple axes of each concept. See the ReadMe included in the Component Hierarchy By System folder for information about its current file structure.

There have been no changes other than the addition of new content since the last release.

Panels and Forms

See the ReadMe included in the Panels and Forms folder for information about its current file structure.

There have been no changes to this file other than the addition of new content since the last release.

Parts

See the ReadMe included in the Part File folder for information about its current file structure.

This file contains all of the parts associated with any LOINC term published in the current release. Note that it does not contain Parts that are used to organize terms in the Component Hierarchy By System.

There have been no changes to this file other than the addition of new content since the last release.

Updates

See the ReadMe included in the Updates folder for information about its current file structure.

For this release and going forward, the CHANGE_REASON_PUBLIC and STATUS_TEXT fields will no longer be considered when determining if a LOINC term has been updated because they contain information for users about term edits but are not directly related to the attributes of a term.

There have been no changes to this file other than the addition of new content since the last release.