LOINC is a voluntary effort housed in the Regenstrief Institute, an internationally respected non-profit medical research organization associated with Indiana University. LOINC was initiated in 1994 by the Regenstrief Institute and developed by Regenstrief and the LOINC committee as a response to the demand for 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.

The purpose of the LOINC® database is to facilitate the exchange and pooling of results for clinical care, outcomes management, and research. Currently, most laboratories and clinical services use HL7 to send their results electronically from their reporting systems to their care systems. However, the tests in these messages are identified by means of their internal, idiosyncratic code values. Thus, the care system cannot fully "understand" and properly file the results they receive unless they either adopt the producer's laboratory codes (which is impossible if they receive results from multiple sources), or invest in the work to map each result producer's code system to their internal code system. LOINC codes are universal identifiers for laboratory and other clinical observations that solve this problem.

The scope of the LOINC effort includes laboratory and other clinical observations. The laboratory portion of the LOINC database contains the usual categories of chemistry, hematology, serology, microbiology (including parasitology and virology), toxicology; as well as categories for drugs and the cell counts, antibiotic susceptibilities, and more. The clinical portion of the LOINC database includes entries for vital signs, hemodynamics, intake/output, EKG, obstetric ultrasound, cardiac echo, urologic imaging, gastroendoscopic procedures, pulmonary ventilator management, selected survey instruments (e.g. Glascow Coma Score, PHQ-9 depression scale, CMS-required patient assessment instruments), and other clinical observations.

LOINC Highlights

Purpose and Design

• 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.
• 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 records apply to all tests with equivalent clinical results. They are not unique per company.
• Distinct LOINC codes are required for each specimen for which your test kit has been calibrated. If your instrument/kit produced one value for each specimen and you recommend its use on two specimens (e.g. whole blood and CSF) two LOINC codes are needed, one for whole blood and one for CSF. If two or more results per specimen are reported (e.g., a control value or a total and a percent), two or more LOINC codes are needed per supported specimen.
• The full LOINC database and RELMA (a program for searching and viewing the LOINC database and mapping local files to LOINC) are available at no cost at http://loinc.org. A CD-ROM version is available at no charge.

 Endorsements and Adoption

• LOINC has been endorsed by the American Clinical Laboratory Association and the College of American Pathologists. It has been adopted as an alternate test reporting code by large commercial laboratories including Quest, LabCorp, Mayo Medical Laboratories, and MDS Labs; large HMOs including Kaiser Permanente and Aetna; governmental organizations including the CDC, DOD, VA, and NLM; and has also been adopted by Germany, Switzerland and two Canadian provinces.
• Current draft proposals for HIPAA electronic claim attachment standards are based on LOINC codes.
• In successive efforts, the Consolidated Health Informatics (CHI) initiative named LOINC as the adopted standard for the domains of laboratory result names, laboratory test orders, drug section label headers, and for federally required patient assessment instruments (questions, answers, and forms) that include functioning and disability content. In addition, the CHI recommendation for text-based reports specifies use of the HL7 CDA, which currently recommends the preferential use of LOINC codes for document titles.
  
• The LOINC effort has been supported by funding from numerous agencies.