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Drs. Sven Van Laere
NOMENCLATURES IN E-HEALTH
Personal
• Sven VAN LAERE
• 4rd year PhD
– Research in nomenclatures in
eHealth systems in Belgium related
to pharmacy
Promotor: Prof. Dr. M. Nyssen
• Previous
– MSc in Engineering: Computer Science
(2013)
– Professional Bachelor in Applied Informatics (2010)
Content Table
• Definition
• Clinical ideas
• History
• Nomenclatures in e-health
• “Coding”
Definition
• Nomenclature
– Nomen
– Calare
- name
- to call
• Definition
– A system of names used in a science, as of
anatomical structures or biological organisms
Clinical idea
• Clinical idea comprise everything we think we know
about health, illness, prevention, investigation, and
treatment
• Clinical ideas are the building blocks of a personal
health record
• Connected clinical ideas are essential for a
connected health service
Clinical idea?
•
•
•
•
•
•
•
•
Diseases
Organisms
Operations
Procedures
Devices
Drugs
Part of the body
…
Working with clinical ideas
• Anyone involved in delivering healthcare
• Recognition, manipulation and interconnection of clinical
ideas is a necessary part of the practice of any clinical
discipline
• Growth of knowledge requires new clinical ideas to be
developed, expressed and tested
• Effective delivery of high-quality health care requires
clinical ideas to be shared in ways that…
– Enhance the quality of the patient care
– Facilitate the growth of clinical knowledge
– Demonstrably deliver value to money
Problem
• It seems very simple
– Clinical ideas are important
– We need to share them
• What’s the problem?
– Hasn’t this problem already been solved?
– Can coding help to this?
Background
• Coding is needed
– Variety of representing a clinical concept
• Example: coronary heart disease
–
–
–
–
–
Diagnosis of myocardial infarction
Raised cardiac enzymes
Myocardial ischaemia
Tripple vessel coronary artery disease
…
Why
• Need for a uniform way of expressing
– Audit
– NLP has not reached the point where free text can
be automatically turned into codes
– Scientific research
– Clinical decision support
–…
History – Text based records
• 1970 – floppy disk invented
– IBM introduced a pilot system in GP practice in Exeter, UK
• 1976 – inktjet printer invented, VHS video tape
introduced
– ICL launched GP system in Otterly St Mary, Exeter, UK
– 1980: Text based patient records stored on mainframe
computer
• expensive pilot project
– Patient records linked by landlines
– Free text allowed users to express clinical ideas
• Easy for data entry
• Problem with retrieval
History – Flags to indicate clinical ideas
• 1982 – compact disks first released
– New Abies computer system
– System allowed each practice to specify a set of 96
important clinical ideas and link them to a patient record
Shared codes
for each
practice?
History – Coding clinical ideas
• 1983 – Lotus 1-2-3 spreadsheet arrived
– Memory got a bit cheaper
– Dated coded entries are added to the system
– The codes are symple mnemonics with no structure
Links between
similar ideas?
=> Still hard to
query the data
History – Organising clinical ideas
• 1984
– Read Codes released (named after James Read)
• Hierarchical set of codes
• Retriaval based on hierarchy
History – Organising clinical ideas
• 1986 – late 1990’s there was a wider use of clinical
systems using coded data
– Read codes in the UK, SNOMED in the US, ICD-9
classification codes in several countries
– The scope of coverage was broadening according to
scientific improvements
– Codes served a useful purpose and continued to be used
– However growing awareness of limitations in simple
approaches to codes and hierarchies
History – Organising clinical ideas
• 1986 – late 1990’s there was a wider use of clinical
systems using coded data
– Read codes in the UK, SNOMED in the US, ICD-9
classification codes in several countries
– The scope of coverage was broadening according to
scientific improvements
– Codes served a useful purpose and continued to be used
– However growing awareness of limitations in simple
approaches to codes and hierarchies
Limitations to code-based hierarchies
• In a code-based hierarchy errors cannot be corrected
without changing the code
– Either the hierarchy stays “wrong” or the code must
change
• For example
– The read code hierarchy suggest that otis media is a type
of “nervous system and sense organ disease”
F: Nervous system and sense organ disease
F5: Ear disease
F52: Suppurative and unspecified otitis media
Limitations to code-based hierarchies
• Suppurative otitis media (middle ear infection) is not
a disorder of the nervous system
– The condition is not a disorder of the nerves or sensors of the ear
– The middle ear belongs anatomically to the respiratory tract
 Logically middle ear infections are a type of respiratory tract infection
F: Nervous system and sense organ disease
F5: Ear disease
F52: Suppurative and unspecified otitis media
Limitations to code-based hierarchies
• Idea of polyhierarchy popped up
– A simple hierarchy is a tree
• Every node has one parent node
– Exception: Most upper parent node (concept)
– Example
• Suppurative acute otitis is…
– An ear disease
– An infectious disease
F: Nervous system and sense organ disease
F5: Ear disease
F52: Suppurative and unspecified otitis media
(POLYHIERARCHY)
Limitations to code-based hierarchies
• Need for non-hierarchical relations
– Suppurative otitis media
• Is caused by “bacteria”
but … is not a type of bacteria
• Occurs in the “middle ear”
but … is not a type of middle ear
F: Nervous system and sense organ disease
F5: Ear disease
F52: Suppurative and unspecified otitis media
ICPC
• International Classification of Primary Care
• Author: WONCA Int. Class. Committee
• Two versions:
– 1987: ICPC-1
– 1998: WHO
(accepted within WHO)
ICPC structure
• bi-axial
• One axis: 17 chapters with an alpha code
based on body systems/problem areas
• Second axis: 7 identical components, with
rubrics bearing a two-digit numeric code
ICPC’s 17 chapters
•
A General and unspecified
•
R Respiratory
•
B Blood, blood forming organs,
lymphatics, spleen
•
S Skin
•
D Digestive
•
T Endocrine, metabolic and
nutritional
•
F Eye
•
U Urology
•
H Ear
•
W Pregnancy, childbirth,
family planning
•
X Female genital system and
breast
•
Y Male genital system
•
Z Social problems
•
K Circulatory
•
L Musculoskeletal
•
N Neurological
•
P Psychological
ICPC’s components
Symptoms and complaints
Diagnostic and preventive procedures
Treatment procedures, medication
Test results
Administrative
Referral and other reasons for encounter
Diseases:
- infectious diseases
- neoplasms
- injuries
- congenital anomalies
- other specific diseases
1-29
30-49
50-59
60-61
62
63-69
70-99
ICPC example
• Heartburn
Code: D03
Chapter
D:
Component 1:
Digestive
Symptom / Complaint
• Pneumonia
Code: R81
Chapter
Component
R:
7:
Respiratory
Disease
Read Codes
• Set of clinical codes designed for Primary Care to
record the every day care of a Patient
• Used in United Kingdom
• Developed by Dr James Read (GP, Loughborough)
• Recognized standard for General Practice
• Hierarchical structure
Key aspects of Read Codes
• Sorted into categories and chapters
• Hierarchical structure
• Combination of letters and numbers
• CaSe-SeNsItIve
• Version 1: Maximum of 4 characters (1983)
Version 2: Maximum of 5 characters (1985)
Read Code chapters
• Diagnoses
– Codes all begin with a capital letter
– e.g. H33 (Asthma), C10E (Type 1 diabetes mellitus)
• Processes of Care
– Codes all begin with a number
– Used to record history, symptoms, examinations, tests, screening, operations
and patient administration, etc
– e.g. 44P (Serum cholesterol), 65E (Influenza vaccination)
• Medication
– Codes all begin with a small case letter
– Automatically entered into the patient record when any treatment is
prescribed
– e.g. bu25 (Aspirin 75mg tablets)
Read Code chapters
Example:
C
C1
C10
C10E
C10E7
Endocrine, nutritional, metabolic and immunity disorders
Other endocrine gland diseases
Diabetes mellitus
Type 1 diabetes mellitus
Type 1 diabetes mellitus with retinopathy
• Could refer to these as “families” of codes – Parent and
Child Codes
• C10 is a parent code to C10E. It is also a child code to C1
• Each code begins the same way as the one before but
contains an extra layer of detail
• This pattern repeats across all chapters
• Enables data to be entered at the required level of detail
Read version 3, Clinical Terms
• 1994: CTv3
– Read version 3, clinical terms
– Clinical Terms version 3
• Intention: develop terminology that could include
specialist practice
• Used in small minority in UK
• Merged with SNOMED => SNOMED CT
ICD
• International Classification of Diseases (and Health
Related Problems)
• Long history and many revisions
• Possibly suffixes
– CM: Clinical Modifications
(e.g. ICD-9-CM)
– PCS: Procedure Classification System (e.g. ICD-10-PCS)
ICD
• End 2014- begin 2015: step-over to ICD-10
– Start in Belgium: January, 2015
SNOMED
• In 1965
– SNOP was developed by the College of American
Pathologists (USA)
• Next 50 years
– several changes on …
• … the number of concepts
• … the covered domains
• … the underlying representation formalism…
• Result: Systematized Nomenclature of Medicine,
Clinical Terms (SNOMED CT) released in 2002
SNOMED CT
• Controlled coded clinical terminology for use
in Electronic Health Records
• Helps in adding meaning to the EHR
• SCT maintained and distributed by the IHTSDO
since 2007
SNOMED CT
• Concept components
– Concepts
– Descriptions
– Relationships
Fully Specified Name (FSN)
• Concepts
Identifier
CONCEPT
SNOMED CT
• Concept
– Own unique identifier
• Numeric identifier of up to 18 digits
• Used to refer between concepts
• Description types
– All concepts have …
• At least one fully specified name
• At least one synonym
80146002
CONCEPT
Preferred terms
SNOMED CT
• Relationships
– Each concept is associated with other concepts by a set of
relationships
– Expressing the defining characteristics of a concept
CONCEPT
CONCEPT
[attribute] has value
CONCEPT
SNOMED CT
• Relationships
– Subtype relationships
• Create a hierarchy linking each concept to more general concepts
• Enable retrieval of specific concepts in response to general concepts
All the supertypes
of appendectomy
SNOMED CT
• Relationships
– Attribute relationships
• Provide additional defining information about concepts
– Why is it different from its supertype
– E.g. sites, causative agents, …
SNOMED CT
• Pre- and post-coordination
– Pre-coordination
Terminology producer provides a single conceptid for the
meaning
• 31978002
– means “fracture of tibia”
SNOMED CT
• Pre- and post-coordination
– Post-coordination
A user composes a combination of conceptids to represent
the meaning
• 31978002 : 272741003 = 7771000
– (fracture of tibia : laterality = left)
– In human readable form …
“fracture of left tibia”
SNOMED CT
• Which one is best to use?
?
SNOMED CT
• Which one is ‘best’ to use?
Pre-coordination
- Single term use
Post-coordination
- Short vocabulary:
each concept once
- Terms are easier to
understand
PRO’s
- Syntax is linked to
semantics
CON’s
- Overuse of terms
- Need for powerful
- Long uninterpretable engine (complex)
strings
Relationship
All included
in UMLS
ICD9
ICPC
ICD10
All crossed with
Snomed-Ct
“Coding”
• Code…
… is a representation applied to a term so that it can be
more readily processed.
• Classification…
… is an arrangement of all elements of a domain, into
groups according to established criteria.
• Nomenclature…
… is an arrangement of concepts, that can be combined
according to specific rules to form more complex
concepts.
2005, S. De Ludignan: Codes,
classifications,
terminologies and nomenclatures
“Coding”
Codes
+ logical groupings
(…is a… relationship)
Classifications
Nomenclatures
+ polymorphism
+ characteristics
ICPC
Codes
Read
Classifications
ICD
Nomenclatures
SNOMED CT
Sources
• Papers
– 2005, S. De Ludignan: Codes, classifications,
terminologies and nomenclatures
– 2006, R. Cornet: A framework for characterizing terminological
systems
• Presentations
– IHTSDO: Why Clinical Terminology Matters
– Health Informatics: Terminology and classification
• Videos
– What is ICD 10?
https://www.youtube.com/watch?v=ZPDgtDDTc8k