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Medical terminologies

Medical terminologies: LOINC
name Logical Observation Identifiers, Names and Codes
summary A public use set of codes and names designed to facilitate in particular the electronic transmission and storing of clinical laboratory results.
clinical focus LOINC codes are universal identifiers for laboratory test results and other clinical observations.
developed by The Regenstrief Institute, Indianapolis and the LOINC committee (initiated in 1994).
introduced 1995
current version LOINC 2.15 and RELMA 3.15 were released on June 6, 2005.

Some seventeen revisions of the LOINC database have been released. Revisions of the LOINC database and/or RELMA program are released 3-4 times per year.
background / derivation LOINC was developed to support the "electronic movement of clinical data from laboratories that produce the data to hospitals, physician's offices, and payers who use the data for clinical care and management purposes" [LOINC background].
  • "The LOINC laboratory terms set provides a standard set of universal names and codes for identifying individual laboratory and clinical results."
  • "LOINC codes allow users to merge clinical results from many sources into one database for patient care, clinical research, or management."
  • "The LOINC database currently contains about 41,000 observation terms."
  • "Nearly 31,000 of these observational terms relate to laboratory testing."
  • "Each record in the LOINC database identifies a clinical observation and contains a formal 6-part name, a unique name for tests identifying code with check digit, synonyms, and other useful information." [LOINC background]
  • Designed to be compatible with HL7 messages.
  • standards

     bullet  LOINC as a standard [OC]

    in use Increasingly widely adopted in the USA. Used in Canada, Germany. Switzerland, Australia, Korea, Estonia, Brazil, and New Zealand.

    LOINC is available in (simplified) Chinese and is to be released in German (translated user manual available October 2005) and Spanish.
    access "The LOINC database can be obtained from the Regenstrief LOINC website ... as a PDF report sorted alphabetically by class, as a tab-delimited ASCII text file, and/or as an Access database. The same web site also provides the 85-page LOINC Users’ Guide (PDF); the free RELMA program, which downloads with full LOINC access to the database; and the RELMA Users’ Manual."

    "The LOINC database and associated documents and programs are copyrighted, but the copyright permits all commercial and noncommercial uses in perpetuity at no cost. If the LOINC database or its contents are distributed as a database, such distributions must include all parts of the formal LOINC term, the LOINC short name, the LOINC code, the deprecated flag, and the copyright. The copyright notice is needed to prevent variants, which would defeat the purpose of this standard. No such notice is required when LOINC codes are used in messages to report test results." [McDonald et al, 2003]
    tools  bullet  RELMA®: a Windows-based program designed to support browsing and searching the LOINC database and mapping local test codes to LOINC codes
    Huff SM, Rocha RA, McDonald CJ, et al. Development of the Logical Observation Identifier Names and Codes (LOINC) Vocabulary. J Am Med Inform Assoc. 1998 May-Jun;5(3):276-92.

    [PubMed Central]

    " The LOINC (Logical Observation Identifier Names and Codes) vocabulary is a set of more than 10,000 names and codes developed for use as observation identifiers in standardized messages exchanged between clinical computer systems. The goal of the study was to create universal names and codes for clinical observations that could be used by all clinical information systems. The LOINC names are structured to facilitate rapid matching, either automated or manual, between local vocabularies and the universal LOINC codes. If LOINC codes are used in clinical messages, each system participating in data exchange needs to match its local vocabulary to the standard vocabulary only once. This will reduce both the time and cost of implementing standardized interfaces. The history of the development of the LOINC vocabulary and the methodology used in its creation are described. "

    McDonald CJ, Huff SM, Suico JG et al. LOINC, a universal standard for identifying laboratory observations: a 5-year update. Clin Chem. 2003 Apr;49(4):624-33.

    [PubMed]   []

    " The Logical Observation Identifier Names and Codes (LOINC) database provides a universal code system for reporting laboratory and other clinical observations. Its purpose is to identify observations in electronic messages such as Health Level Seven (HL7) observation messages, so that when hospitals, health maintenance organizations, pharmaceutical manufacturers, researchers, and public health departments receive such messages from multiple sources, they can automatically file the results in the right slots of their medical records, research, and/or public health systems. For each observation, the database includes a code (of which 25 000 are laboratory test observations), a long formal name, a "short" 30-character name, and synonyms. The database comes with a mapping program called Regenstrief LOINC Mapping Assistant (RELMA™) to assist the mapping of local test codes to LOINC codes and to facilitate browsing of the LOINC results. Both LOINC and RELMA are available at no cost from The LOINC medical database carries records for>30 000 different observations. LOINC codes are being used by large reference laboratories and federal agencies, e.g., the CDC and the Department of Veterans Affairs, and are part of the Health Insurance Portability and Accountability Act (HIPAA) attachment proposal. Internationally, they have been adopted in Switzerland, Hong Kong, Australia, and Canada, and by the German national standards organization, the Deutsches Instituts fur Normung. Laboratories should include LOINC codes in their outbound HL7 messages so that clinical and research clients can easily integrate these results into their clinical and research repositories. Laboratories should also encourage instrument vendors to deliver LOINC codes in their instrument outputs and demand LOINC codes in HL7 messages they get from reference laboratories to avoid the need to lump so many referral tests under the "send out lab" code. "

    Bakken S, Cimino JJ, Haskell R, Kukafka R, Matsumoto C, Chan GK, et al. Evaluation of the clinical LOINC (Logical Observation Identifiers, Names, and Codes) semantic structure as a terminology model for standardized assessment measures. J Am Med Inform Assoc 2000;7:529-538

    [PubMed]   [PubMed Central]

    " OBJECTIVE: The purpose of this study was to test the adequacy of the Clinical LOINC (Logical Observation Identifiers, Names, and Codes) semantic structure as a terminology model for standardized assessment measures. METHODS: After extension of the definitions, 1, 096 items from 35 standardized assessment instruments were dissected into the elements of the Clinical LOINC semantic structure. An additional coder dissected at least one randomly selected item from each instrument. When multiple scale types occurred in a single instrument, a second coder dissected one randomly selected item representative of each scale type. RESULTS: The results support the adequacy of the Clinical LOINC semantic structure as a terminology model for standardized assessments. Using the revised definitions, the coders were able to dissect into the elements of Clinical LOINC all the standardized assessment items in the sample instruments. Percentage agreement for each element was as follows: component, 100 percent; property, 87.8 percent; timing, 82.9 percent; system/sample, 100 percent; scale, 92.6 percent; and method, 97.6 percent. DISCUSSION: This evaluation was an initial step toward the representation of standardized assessment items in a manner that facilitates data sharing and re-use. Further clarification of the definitions, especially those related to time and property, is required to improve inter-rater reliability and to harmonize the representations with similar items already in LOINC. "

    contact Regenstrief Institute, Inc.
    1050 Wishard Boulevard
    Indianapolis, IN 46202, USA

    Tel: (317) 630-7433

    links  bullet  LOINC  bullet  Regenstrief Institute  bullet  LOINC download [OC]  bullet  LOINC as a standard [OC]
    page history
    Entry on OpenClinical: 15 July 2005
    Last main update: 29 July 2005

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