NATIONAL CODE LIST OF
LABORATORY ITEMS ÔÇô BASIC INFORMATION
One of the important conceptual foundations in the field
of standardisation of laboratory fields is the National code list of laboratory
items (N─îLP in Czech), introduced in 1997 by the methodological instructions of
the Ministry of Health of the Czech Republic (see Bulletin of Ministry of
Health CR, volume 1997, issue 7, July 1997, pages 2 to 4) and declared in an
innovated form in connection with the Data standard DS 2.01.01 (and higher) in
2002 (see National code list of laboratory items) and with the Data standard DS
3.01.01 (and higher) in 2003. The Bulletin of Ministry of Health CR, 2015,
issue 20, declared further development of N─îLP in connection with the Data
standard series 4 (development and maintenance of DS3 was brought to an
The N─îLP is based on the IUPA/IFCC nomenclature for
creating NPU codes. In the beginning, the basis for the N─îLP and the NPU were
similar (NPU codes were not originally intended to be used as a code list in
contrast to N─îLP that was meant to purely serve this purpose), but a gradual
development lead, in some cases, to different constructions.
The N─îLP is continuously expanded in the mutual
cooperation of leading experts from societies of clinical fields with
laboratory component of the Czech Medical Association (CzMA) and the Czech
Society of Medical Informatics and Scientific Information CzMA and the Ministry
of Health CR. Its current version can be found on www.dastacr.cz or
on web services of the Ministry of Health CR.
In practice, the N─îLP is used mainly by the Data Standard
of the Ministry of Health of Czech Rep. (DASTA), laboratory information systems
(LIS), some hospital information systems (NIS), and it is expected to be used
by more sophisticated information systems of general practitioners (ISPL). The
N─îLP is further used when creating standards in laboratory and clinical fields,
within the EQA control systems, in the process of creating encyclopedias of
laboratory fields, texts of repetitoria used in education, etc.
The N─îLP is continuously expanded, modified, and
improved, especially concerning creating standards in laboratory and clinical
The National code list of laboratory items
From the informatics point of view, the national code
list of laboratory items (N─îLP in Czech) is a data file containing basic
definitions and descriptions of laboratory items to the extent necessary for
the Data Standard of the Ministry of Health CR and routine laboratory practice.
The N─îLP further contains basic definitions and information necessary to create
standards of effective medical care and to create standards of quality
management in clinical laboratories. See [NCLPPOL].
It is further necessary for many healthcare information
systems (LIS, NIS, ISPL).
It is made up using elements stored in internal code
The above-mentioned mainly include code lists of systems,
components, procedures, kind-of-properties, and units.
A system is a bounded arrangement of a set of elements and a
set of relationships between these elements. It is a subject of a laboratory
test (biological material; e.g. plasma). See the systems code list - [NCLPSYST].
A component is a definable part of a system. It is a measured
quantity itself (e.g. glucose). See the components code list ÔÇô [NCLPKOMP].
Kind-of-property is a characteristic of a component (subject) that can be
quantitatively differentiated and qualitatively determined (e.g. amount of
substance, length, colour). See the kind-of-properties code list - [NCLPDRVL] and N─îLP: Kind-of-properties.
A unit is a quantity accepted by a convention for a
quantitative comparison of the same kind of quantities. It is closely related
to kind-of-property. See the kind-of-properties and units code list - [NCLPJEDN] and SI units.
A procedure is a laboratory examination procedure used to
obtain characteristics of components and their possible quantitative
comparison. See the procedures code list - [NCLPPROC].
A key is assigned to every laboratory item. It is a
five-character (a positive integer) unambiguous element used primarily by
computer information systems and the data standard to unequivocally identify an
A laboratory item is a quantity defined in N─îLP using the five above
mentioned principal elements (system, component, kind-of-property, unit, and
This five-element definition has always assigned a unique
identification key, which is considered a part of the basic item's definition.
The basic definition of a laboratory item has other data
appended ÔÇô the ones necessary for information systems, data standard, standards
of effective healthcare, and standards of quality management in clinical
laboratories. These include, in particular, a name of the laboratory item, a
component class, a gestion, an item type in terms of a dialog, an origin, a
value format, and other. For each item, links to a range of other mandatory or
optional information are available.
Construction of a laboratory item is based on the SKDJ
and procedures code lists.
The SKDJ code list is generated from components, systems,
kind-of-properties, and units code lists.
Kind-of-properties code list is connected to the units
This is how an author creating a new N─îLP item proceeds.
An average user does not need to know about the existence of the SKDJ code
The SKDJ code list is important for information systems
as relevant links to corresponding IFCC, IUPAC, and other code lists are made
A local code list of
laboratory items is intended for
particular laboratory users.
Based on a National code list of laboratory items (N─îLP)
there are local code lists of laboratory items (L─îLP) generated. They are a
subset of N─îLP and have clearly defined rules for their generation and mutual
relations. L─îLP respect the needs of specific laboratories. See [LCLPPOL].
A local code list of laboratory items is always generated
in a direct connection to a specific suitable N─îLP item. Thus all data
associated with the N─îLP item are also available for the corresponding L─îLP
item. L─îLP items have other necessary data of local character attached.
For a correct realization of these connections there
exists a user version of an information system SLP as well as a user version of
─îLP software (its distribution is carried out by the Ministry of Health CR
since 2001 and can be found at www.dastacr.cz),
derived from a reference author's version of SLP information system (of which
it is a subset).
Detailed descriptions of the procedures for creating
links between N─îLP and L─îLP can be found in ─îLP software and SLP information
system together with suitable tools for adding other data.
The name of the N─îLP
laboratory item is constructed
using individual elements:
ÔÇó a name of the component (up to 55 characters),
ÔÇó abbreviated name of the system (code or text up to 32
ÔÇó abbreviated name of the kind-of-property (code or text up
to 24 characters),
ÔÇó unit (up to 20 characters)
ÔÇó abbreviated name of the procedure (code or text up to 32
In practice, the length does not exceed 120 characters.
The notation structure is as follows:
kind-of-property [unit] procedure)
Characters ÔÇť ( ; [ ] )
ÔÇť are inserted automatically when the name is created ÔÇô individual texts are
taken from the corresponding code lists. Characters ÔÇť ( ) ÔÇť can also be found
in the name of the component or the name of the system.
The above-mentioned structure is the basic name of the
laboratory item. It should be used in this way to unambiguously identify the
An abbreviated variant is also possible ÔÇô it does not
characterise the procedure. It is suitable when there is no need to emphasize
Both notations are equivalent in their use.
Names of the laboratory item are also accompanied by
their synonyms. Synonyms are not intended for ordinary use in documents
concerning standards of effective healthcare or quality management in clinical
laboratories. They only serve to provide links to older or other technical
A special type of synonyms includes a chemical name
according to IUPAC (for some, mostly biochemical, items).
Component classes make it possible to classify the item into one or
more groups (e.g. 'proteins', 'enzymes', 'tumor markers'). They are used for
searching, grouping in search lists, and further processing of items for the
needs of encyclopedias and lists. The relevant classes can be assigned to an
item by choosing from the code list of components - [NCLPTK]. The main class is stored in the category item and can be used to create search
Gestion states for which of the professional societies of
the Czech Medical Association of J. E. Purkyn─Ť the definition was created by an
author. The information is only indicative.
See the gestion code list - [NCLPTNG].
Variants for electronic
ordering of examination (marked
as ÔÇťDSÔÇŁ in the N─îLP dialog) make it possible to indicate whether an item can be
used for electronic ordering of examination and which variant can be
See the code list of variants for electronic ordering of
examination - [NCLPVEOV].
Item type in terms of a dialog is assigned from a corresponding code list of item types
in terms of a dialog. Every N─îLP item has one such item type assigned.
The basic item types include 'numerical', 'text
formalized', 'text non-formalized', and 'structured' (for microbiological findings,
search lists, and special structures). Text formalized item types have assigned
links to corresponding text result matrices (MTVs). Numerical item types have
assigned information concerning numerical range, display format, and possibly
also optional data on reference intervals. Definitions of the structures are
available for structured item types.
See types of N─îLP items in terms of a dialog in [NCLPTYPD] code list.
Value format is directly connected with item type in terms of a
dialog. It defines the form and the display format of the value of the
corresponding item. See the value format code list. Every N─îLP item has
assigned one value format. It is, among other things, used to derive specific
data blocks enabling the communication of the results ('Vri' data blocks).
See types of N─îLP items in terms of value format in [NCLPFH] code list.
A format of the reference
intervals is connected both to
the item type in terms of a dialog and the value format. It defines whether the
reference intervals are displayed for the item and if yes it determines the
display format. It has meaning for numerical items. See the format of the
reference intervals code list - [NCLPFRM].
MTVs are the so-called ÔÇťtext result matricesÔÇŁ. These are
predefined unambiguous sets of texts used for formalized communication of
results in a text form.
They are used to communicate values of items that have
text as a result of examination (e.g. colour, shape, predefined list of
characteristics or attributes, etc.). MTVs are also used to communicate
substitutes of item values where there is not possible to fully determine the
result due to a collision (e.g. collision state of the material, atypical
situation, etc.). See MTV code list - [NCLPMTV].
Origin is a special type designation of a laboratory item
with regard to a form in which the item is created or with regard to its
further processing and use. See types of items in terms of their origin code
Due to the importance of this information for the
creation of standards, the code list of origins is further elaborated.
See types of the N─îLP items in terms of origin,
description in [NCLPVZNK] code
The relationship in N─îLP and
L─îLP between the type of items in terms of origin and the type of items in
terms of a dialog.
See relationships in the item description in N─îLP, L─îLP,
There are many connections and relations between the N─îLP
items themselves and the N─îLP items and other code lists and files. They are
not only important for DS, but also information systems, laboratory
technologies, clinical interpretations, many other standards, and possibly also
for SOP documents and others.
To describe the relationships, there exist other code
lists as an optional part of the N─îLP.
For more information see:
relations between items and with items - general
relations between N─îLP items - general
relations between N─îLP items - definitions