ISO 17115:2020

INTERNATIONAL ISO
STANDARD 17115
Second edition
2020-05
Health informatics — Representation
of categorial structures of terminology
(CatStructure)
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General . 1
3.2 Relations between concepts . 3
4 Categorial structure description . 4
4.1 General . 4
4.2 Precise goal of the categorial structure . 4
4.3 Generic concepts . 4
4.4 Type of characteristic . 6
4.5 Generic concept relations . 7
Bibliography . 8
Foreword
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics.
This second edition cancels and replaces the first edition (ISO 17115:2007), which has been technically
revised. The main changes compared to the previous edition are as follows:
— change in title and expansion of scope;
— reference to the ISO 17117 series which has further developed terms, definitions and characteristics
of healthcare terminologies;
— inclusion of requirements for categorial structures to support the key purpose of standardization
and clarification of terminologies in healthcare.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

Introduction
Health terminology is complex and multifaceted, more so than most language domains. It has been
estimated that between 500 000 and 45 million different concepts are needed to adequately describe
conditions of patients and populations, actions in healthcare and related concepts, such as biomedical
molecules, genes, organisms, technical methods and social concepts.
To adequately represent and especially to process this complexity, simple coding schemes are
inadequate and formal multidimensional concept representation systems are better suited. The
differences in terminology are understandable as this kind of work is highly interdisciplinary and
integrates knowledge from linguistics, philosophy, informatics and health sciences, and there is room
for misunderstanding between disciplines.
Several such formal systems exist but systems and underlying philosophy are described in different
ways. The system itself can, for example, be called an ontology, medical entity dictionary, coding and
reference model or reference terminology.
Computer-based processing and interchange of medical or clinical information uses various kinds of
terminological systems of concepts to represent that information, such as controlled vocabularies,
classifications, nomenclatures, terminologies and thesauri, with or without coding schemes.
The specific terminological issues in the field of health informatics are the following:
a) a large number of different terminological systems are available in different clinical specialties;
b) a large overlap among the subject fields involved;
c) a large number of codes and rubrics, typically in the order of magnitude of 10 000 to 100 000 entries,
in commonly used terminological systems;
d) an increasing need for re-use of coded data in different health-care contexts;
e) polysemy across and sometimes within clinical specialties.
The integration of computer-based medical records and administrative information systems design is
supported by a uniform way to represent the meaning of medical concepts using terminologies. Such
uniformity ensures that the EHR receiving a message will catch the meaning intended by the sender
EHR and not just the string of characters used to represent that meaning. It is not possible to impose a
rigidly uniform standardized natural language clinical terminology on healthcare providers due to the
need for different levels of specificity based upon the clinical use case.
This document is intended to be read in conjunction with ISO 17117 and contains references to
Reference [16].
A domain specific semantic model has been envisioned and applied in a series of specific European
standards (EN) and International Standards (ISO) on various subject fields to describe a set of categorial
structures. This is partially important where subject fields overlap. There are more than 10 different
International Standards on categorial structures and this number is increasing every year.
Potential uses for this document are to
a) describe formal definitions, parts of definitions and how they are related, and
b) describe patterns for concept representation in a particular domain.
This document also
a) facilitates the construction of new terminological systems in a regular form which will increase
their coherence and expressiveness,
b) facilitates maintenance of terminological systems,
c) increases consistency and coherence of existing terminological systems,
d) allows systematic cross-references between items of different types of terminological systems,
e) facilitates convergence among terminological systems and makes explicit the overlap between
different health care domains terminological systems,
f) provide elements for negotiation about integration of different terminological systems into
information systems between the respective developers, and
g) enable the systematic evaluation of terminological systems.
The target groups for this document are
a) developers of concept representation systems for different health care domains,
b) developers of standards for concept representation, especially those describing domain concept
models,
c) information modellers, knowledge engineers, and standards developers building information
models for health information systems such as electronic health records and decision support
systems,
d) developers of information systems that require an explicit system of concepts for internal
organization, data warehouse management and middleware services,
e) designers of specialized standard healthcare terminological categorial structures,
f) developers of healthcare terminological systems including classifications and coding systems,
g) producers of services for terminological systems and designers of software including applications
for natural language processing,
h) information modelers, knowledge engineers, and standards developers building models for health
information management systems,
i) developers of information systems that require an explicit system of concepts, and
j) developers of mark-up standards for representation of healthcare documents.
This document is informed by other standards, with clarifications and examples appropriate to
healthcare.
This document has been developed for use as an integrated part of computer-based applications and for
the electronic healthcare record. It would be of limited value for manual use.
vi © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 17115:2020(E)
Health informatics — Representation of categorial
structures of terminology (CatStructure)
1 Scope
The purpose of this document is to
a) define a set of basic concepts required to describe formal concept representation systems,
especially for health sciences,
b) describe representation of concepts and characteristics, for use especially in formal computer-
based concept representation systems,
c) describe the characteristics which synthetically describe the organisation and content of a
terminological system in health,
d) support the development of specific standards on categorial structures for particular healthcare
subject fields with the minimum requirements to support meaningful exchange of information.
This document is not suitable for, or intended for use, by individual clinicians or hospital administrators.
It is not the purpose of this document to standardize the end user classification or to conflict with the
concept systems embedded in national practice and languages.
Topics considered outside the scope of this document include
— enumeration of axiomatic concepts and semantic links, and
— detailed content of health terminology systems (classifications, nomenclatures or reference
terminology of health concepts).
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 General
3.1.1
categorial structure
reference terminology model
minimal set of domain constraints (3.1.5) for representing concept systems (3.1.2) in a subject field (3.1.7)
3.1.2
concept system
system of concepts
set of concepts (3.1.8) structured according to the relations among them
3.1.3
type of characteristic
characterizing category
category of characteristics (3.1.4) which serves as the criterion of subdivision when establishing concept
systems (3.1.2)
EXAMPLE The type of characteristics ‘colour’ includes being red, blue, green, etc. The type of characteristics
‘material’ includes made of wood, metal, etc.
3.1.4
ch
...