LOINC Release Notes

Version 2.73, August 2022

Beginning with the previous release in Feb. 2022, we streamlined the LOINC release structure to make it easier for users to access all of the necessary files. The LOINC table and accessory files are included in a single archive, and RELMA is provided as a separate download file. Individual accessory files are no longer available as separate downloads.

Table of contents:

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

Type New terms Total
Laboratory (type 1) 283 59506
Clinical (type 2) 307 26364
Attachments (type 3) 0 1157
Survey (type 4) 221 12052
Total 811 99079

Totals by Status

Status Number of terms
Active 90486
Deprecated 3817
Discouraged 1507
Trial 3269

Term Status changes

Old Status New Status Number of terms Type
Active Deprecated 88 2 Clinical, 86 Survey
Active Discouraged 8 1 Clinical, 7 Survey

Edits by change type

Change type (field name CHNG_TYP) CHNG_TYP definition Number of terms
NAM Component update 35
MAJ Update to one of 5 other primary axes other than Component 13
MIN Update to a secondary field - see Updates file Readme for the full list 20775
DEL Status changed to Deprecated 88
UND Status changed from Deprecated to Active 0
PANEL Change in the child elements or conditionality of one or more child elements in the panel or a sub-panel contained in the panel 42
Total 20953

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

New laboratory content highlights

  • Over 80 new microbiology terms, 8 of which are related to the pandemic virus, SARS-CoV-2 (COVID-19). Many others were created to support specialized microorganism testing by the CDC.
  • 10 new microbiology terms related to supporting Monkeypox virus testing.
  • 31 new chemistry terms, including macromolecular proteins, additional liver fibrosis scoring, and others.
  • 55 new allergy terms for the measurement of IgG and IgG4 levels for various allergens.
  • 10 new drug/toxicology terms for testing performed on various specimens.
  • 19 new molecular genetic tests, including several multigene studies for cancer, platelet disorders, genetic disease analysis, and various other conditions.

New clinical content highlights

  • 13 new radiology procedures, including terms for guidance for cryoablation and guidance for percutaneous biopsies.
  • 19 new clinical terms, including pure tone bone and air conduction threshold audiometry panels and terms supporting the National POLST Portable Medical Orders form.
  • Over 200 new document ontology terms, including inpatient and outpatient progress notes and discharge summary notes.
  • Ongoing work with the Gender Harmony Project has resulted in several new trial terms which will be finalized as that committee completes recommendations.

New survey content

  • Orthopedic survey instruments: Knee Society Score pre-op panel (100159-3), Knee Society Score post-op panel (100203-9), Harris Hip Score panel (100283-1).
  • Mental health related survey instruments: Five Facet Mindfulness Questionnaire panel (100280-7), Brief Resilience Scale panel (100360-7) and Center for Epidemiologic Studies Depression panel (100766-5) for the use with the project Orchestra-Connecting European Cohorts to Increase Common and Effective Response to SARS-CoV-2 Pandemic.
  • SDOH instruments: Behavioral screening elder mistreatment (100307-8) and the Norwalk Community Health Center Screening Tool (100353-2) for the Gravity Project, which is a national collaborative effort to help reduce barriers to interoperable social risk and protective factors documentation.

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
  • Removed the Method from several terms that represent generic concepts to allow broader use
  • Updated several sets of terms from TRIAL to ACTIVE status

Changes based on community input

  • Corrected the example units and example UCUM units for several terms related to metabolic activity
  • Corrected several minor typos in Components and display names
  • 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 2.73 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 2.72 and version 2.73, such as from TRIAL to ACTIVE. It does not contain terms that were newly added in 2.73. 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 2.72 and version 2.73, 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 2.73 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.

1. The LOINC Groups project is a work in progress. The contents of this file may change from release to release as we receive feedback from users and refine our processes. 2. The contents of the file and the groupings MUST be validated by the user prior to implementation in any aspect of clinical care. We have created Groups that may be useful in specific contexts, but these Groups have not been vetted for use in either patient care or research and should be used with caution.

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.

One new linguistic variant, Ukrainian, has been introduced in LOINC version 2.73.

Updated linguistic variants are generally based on the previous release version (i.e., LOINC version 2.72 is translated for inclusion in the 2.73 release).

Updated content for the LOINC 2.73 release has been provided by the translation for the following linguistic variants:

  • zh_CN Chinese (CHINA)
  • fr_CA French (CANADA)
  • de_AT German (AUSTRIA)
  • de_DE German (GERMANY)
  • pl_PL Polish (POLAND)
  • uk_UA Ukraine (UKRAINIAN)
  • it_IT Italian (ITALY)
  • es_ES Spanish (SPAIN)
  • nl_NL Dutch (NETHERLANDS)

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

Linguistic variant Version last updated
Chinese (CHINA) 2.73
Dutch (NETHERLANDS) 2.73
Estonian (ESTONIA) 2.23
French (BELGIUM) 2.47
French (CANADA) 2.73
French (FRANCE) 2.70
German (AUSTRIA) 2.73
German (GERMANY) 2.73
Greek (GREECE) 2.34
Italian (ITALY) 2.73
Korean (KOREA, REPUBLIC OF) 2.27
Polish (POLAND) 2.73
Portuguese (BRAZIL) 2.51
Russian (RUSSIAN FEDERATION) 2.65
Spanish (ARGENTINA) 2.15
Spanish (SPAIN) 2.73
Spanish (MEXICO) 2.72
Turkish (TURKEY) 2.56
Ukrainian (UKRAINE) 2.73

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.

The LoincPartLink_Supplementary file exceeds the row capacity of Excel and LibreOffice.

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.

Knowledge Base

Users’ Guide

Search Syntax

RELMA

FAQ