NPU Terminology

NPU Database

The current version of the C-NPU Database (in English) is available for direct download and as interactive search page.

A larger set of NPU codes and associated terminological information may be downloaded. Updated versions are published each month.

Three different data sets are published (available from: They may be downloaded either as the full database content or as 'updates since last month':

  • NPU Definitions - contains all NPU codes in the database - both active and retired. The definitions are presented in the shortened form frequently used as terms for the result types. For purposes of filtering and sorting the following columns contain the same string split into sections corresponding to the structural parts of the syntax. The last columns contain additional information about the assigned field of laboratory science, the result scale type and the status (active/retired) of the code. The file also contains coding for local Danish use - identified with 'DNK' instead of 'NPU'. Note that some columns are empty - for technical reasons we have kept discontinued columns in place in the file.
  • NPU List - contains 'groups' of NPU codes established in the terminology. They are used mainly for ordering of investigations. The columns 'List code value' and 'List Item pos no.' together with the NPU code value specifies the structure of the groups - the group header in a group has 'List Item pos no' '0', and the content items follow in the order specified. The content items are examples of possible content; the set is neither mandatory nor necessarily complete.
  • Elementer - (term elements) - contains all the terms used in writing the NPU definitions, and their terminological references. The last column for some entries contains - as an experiment - an explanation or definition for terms that have no external source of reference.
    (The IDs do look somewhat inconsistent, as older IDs contain included reference information while newer element IDs do not).

Structure of the NPU Terminology

The NPU terminology identifies types of result values, for use in reporting laboratory results. The definitions have a uniform structure and use a referenced vocabulary.

In the medical field, the outcome of a patient examination is information about certain properties of that patient. 
The NPU nomenclature identifies laboratory result items by specifying these properties in a formal definition structure.

The structured definitions describe

  • the part of the universe that is studied (the system)
  • the component that is examined in that system
  • the estimated kind-of-property of the component in that system
  • measurement unit and specifications where relevant

This is expressed using internationally recognised and referenced terms set in a prescribed syntax and identified with a code:

measurement unit

Examples of structured NPU definitions:

Sodium ion; 
substance concentration 
millimole per litre 

Gliadin antibody(Immunoglobulin G); 
mass concentration 
milligram per litre 

An abbreviated form of the definition may serve as a precise term for the property in laboratory reports and health care records:

  • U—Sodium ion; subst.c. = [result value] mmol/l
  • P—Gliadin antibody (IgG); mass c. = [result value] mg/l

The use of SI units and of internationally recognised and referenced terms from the clinical laboratory sciences enables translation of the structured definitions into other languages without loss of precision or meaning. Translation of each term within the definition structure will leave the defined concept unchanged by translation.