"LOINC was initiated in 1994 by Clem McDonald, an investigator at the Regenstrief Institute, which is an internationally respected non-profit medical research organization associated with Indiana University. Regenstrief organized the LOINC committee to develop a common terminology for laboratory and clinical observations because there was a growing trend to send clinical data electronically from laboratories and other data producers to hospitals, physician's offices, and payers who use the data for clinical care and management purposes.
At the time, and still today, 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. As a result, receiving care system cannot fully "understand" and properly file the results they receive unless they either adopt the producer's test 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.
Here's the problem that LOINC solves: LOINC provides universal codes and names that provide the global lingua franca for identifying tests and observations."