There are differences between the requirements for organizing concepts and orderable concepts:

  • Organizing codes need to subsume something or they are not useful.
  • Orders need to be fully specified. The lab needs to have enough information to know what analysis needs to be performed

While many concepts in the new Class serve both purposes, some act solely as organizers and are not included in lab orders. Furthermore, when the new concepts are used in orders they will nearly always be post coordinated with specimen and/or other information to make the order information complete and unambiguous. The new codes alone do not have enough information for a well-defined order. In the United States, CLIA requires a test description / test name to accompany codes. This is a second identifier.

The approach used to make the new LABORDERS.ONTOLOGY codes follows. All Lab LOINC concepts were analyzed and identified the set of unique concepts that are combinations of Component, System (specimen), and a new general Property called measurement. Measurement subsumes more specific kinds of measurements like mass concentration, substance concentration, number fraction, etc. The complete list of Property values that are subsumed by measurement are listed below. There are over 25,000 combinations of Component and System. With version 2.81, there was an arbitrary decision to only make new codes for the 2,547 items where the new concept subsumes three or more result concepts. The new concepts will have a status of “code for trial use.” After real world experience is obtained, some of these codes may be inactivated. The use of the new codes is entirely optional, and they do not replace any of the existing panel codes or other lab codes that are tagged as orderable. There may be additional LABORDERS.ONTOLOGY concepts in the future.

A potential risk with the creation of the new concepts is that they will be misused. Making these more abstract orderable concepts is a policy change for LOINC and the new policy will be unfamiliar to LOINC users. These new concepts should never, ever be sent as result codes in result messages. Examples, tutorials, education, and training will be provided to emphasize the correct use of these new concepts and to try to prevent their misuse.