Transcript Document 713035

Clinical templates, registries
and e-terminologies
from paper-based terminology systems to
semantic interoperability
Angelo Rossi Mori
National Research Council, Rome - Italy
HL7 / Vocabulary TC & CEN / TC251 / WG II
Contents
• key requisites for e-terminologies
new roles for e-terminologies
• 4 kinds of e-terminologies
usages, topics, actors
• 3 pillars for semantic interoperability
(repositories, templates, value domains)
Key requisites for e-terminologies
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support multiple usages of clinical data
within information systems
build coherent "families”, each made of
many specialised coding schemes
restore continuum between content
(values) and containers (data elements)
achieve complete interoperability
among applications
Co-existence and specialisation
• co-existence of families of coding schemes
within the same information system
(each scheme is conceived to satisfy a purpose)
• specialised coding schemes differ
– by amount of details
(e.g. classification vs nomenclature)
– by kind of details
(e.g. classifications with various purposes)
Specialisation of coding schemes
• each coding scheme is conceived
for a precise purpose and context:
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4-digit ICD
LOINC
SNOMED
CTP4
MeSH
...
statistics
orders / prescriptions
clinical detail
claims / reimboursement
information retrieval
3 levels of clinical expressions
the same data should be represented
by the appropriate system
according to the actual task and purpose
• unconstrained, spontaneous text
(it could be either dictated or typed text, or
an entry from a predefined local vocabulary)
• entry of a detailed nomenclature
• class (grouping conceived for a purpose)
clinical expressions in context
task
terminological phrase
admission
operation for lower third rectum cancer
scheduling abdominoperineal amputation of rectum
reporting
low anterior resection of rectum
with double stapling technique
discharge
other anterior resection of rectum, ICD-9-CM 48.63
reimbours.
operation for rectum cancer, DRG 147
cost
analysis
anterior resection of the rectum
with double stapling technique
quality
assurance
low anterior resection of rectum without temporary
colostomy and operation for lower third rectum cancer
Different but coherent
• coherence among coding schemes
– unnecessary diversity shall be removed
– motivated diversity shall be fixed
• coherence between
– local expressions for "private" recording, and
– "public" expressions for communication
and comparisons
Representing a statement / fact
• huge pre-coordinated nomenclature
• combinatorial nomenclature
with controlled post-coordination (one code)
• multi-axial nomenclature — without rules
to produce combined expressions and codes
(repeat multiple values in one field)
• independent value domains
for a set of related data elements
(clinical template arranging multiple fields)
New roles of e-terminology
• NO MORE "just labels"
operational perspective of (clinical) data
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key for retrieval of operative data
from master tables and knowledge bases
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internal tables, within applications
commercial drug databases
triggers, e.g. warnings and alarms
Arden syntax, MLM and decision support
...
Contents
• key requisites for e-terminologies
new roles for e-terminologies
• 4 kinds of e-terminologies
usages, topics, actors
• 3 pillars for semantic interoperability
(repositories, templates, value domains)
Usages, topics, actors - 1
• triggers for services within applications
– life-cycle states (messages, workflows, activities)
– names of messages and segments
system developers
HL7 maintains closed tables - CNE
• organisational & administrative parameters
– sex, race, religion, dietary preferences
facility managers
HL7 maintains reference tables - CWE
Usages, topics, actors - 2
• clinical / communication & scheduling
– lab tests, document names, activity names
master tables builders & users
HL7 endorses adequate domains
• clinical / recording
– findings, History & Physical,
– assessments, diagnoses, health issues
recording professionals
HL7 registers compatible domains
Contents
• key requisites for e-terminologies
new roles for e-terminologies
• 4 kinds of e-terminologies
usages, topics, actors
• 3 pillars for semantic interoperability
(repositories, templates, value domains)
The emerging needs
• satisfy needs of
– sub-communities (diabetes, cancer, ESRD)
– ad-hoc information flows (e.g. CDC, HCFA)
• assure more flexibility of messages
and documents
• maintain control over the process
through registration and support databases
i.e. decentralise but avoid the chaos
achieve “semantic interoperability”
3 pillars for real interoperability
The emerging strategy is based on 3 pillars:
1. data dictionaries and metadata registries,
including names of observations (LOINC)
2. clinical templates
3. tables with enumerated value domains
unresolved issue:
how to maintain the respective databases ?
1. metadata registries
• Simple list of data elements
with either answer-list or ranges of values
(e.g. see “names for observations” in LOINC;
see also XDT/Germany, ISO 11179, ASTM E1384)
• Integrated repository
with uniform representation of data elements
Extension of the RIM:
each data element should be explicitly
registered as a child / refinement of a RIM class,
under control of the respective HL7-TC
HL7 registered entry
elementary entry
RIM attribute
locally registered entry
we will need further steps
• harmonise data elements and tables across
different systems/organisations
• facilitate assignment
of actual data elements of end-users
to data elements adopted by secondary users
(CDC, HCFA, …)
• facilitate feedback
from end-users to secondary users
2. clinical templates
to aggregate data elements from the repository
(or from the RIM) into meaningful fragments
i.e. building blocks
to allow for flexible messages
aggregates (and the related data elements)
need a registration process
under the control of HL7 TCs
examples of aggregates
• batteries of lab tests
• blood pressure (systolic+diastolic)
+ circumstances (patient's position, device)
• pathways in USAM-RIM (mood+links table)
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DICOM-SR (templates + context groups)
clusters in ENV 13606-2
clinical templates in HL7
CMET in the HL7 HMD ?
a potential clinical example
template name: “description of duodenoscopy”
data element
lumen
contents
wall
mucosa
hemorrhage
flat lesions
protrusions
…
value domain (for duodenoscopy)
{normal, spasm, stenosis, …}
{blood, biliary stones, parasites, …}
{rigid, decreased distensibility, …}
{atrophic, granular, hyperemic, …}
{mucosal bleeding, varices, …}
{aphta, infiltration, …}
{papule, polyp, …}
...
(from “Nomenclature of Digestive Endoscopy”, OMED, 1994)
Example of legal requirements
template name: “data items for nursing file”
data elements
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Care of hygiene
Care of mobility
Care of elimination
Care of food
Food by probe
Specific care of the mouth
Handling emotional problem
Care for disorientated patient
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• Vital parameter registration
• Physical parameter registration
• Surveillance of tractions, plasters
• Withdrawal of blood
• Administration of medications
• Surveillance of drips
• Care for closed wound
• Care for open wound
(Belgian law of 14.08.1987)
repository entry
elementary entry
clinical template
3. Value domains
Hundreds of explicit tables
with enumerated value domains
admitted values for each data element
of the RIM and of the repository,
considering restrictions due to clinical templates
"e-terminologies in context"
coordinated by HL7 vocabulary TC
elementary entry
is restriction of
has domain 
value domain
numeric range
enumerated table
HL vocab entry
HL7 table
external reference
a Cluster in CEN 13606-2
"original component complex
used to aggregate data items and/or other clusters
to represent a compound concept.
EXAMPLES.
• A blood pressure measurement consisting of systolic and
diastolic pressure,
• a collection or closely related clinical findings,
• results of a battery of laboratory investigations,
• a treatment schedule consisting of several individually specified
preparations or dosages.”
kinds of Clusters (CEN 13606-2)
• a set of closely inter-related symptoms
(e.g. a cough productive of discoloured sputum and blood);
• a single act of physical examination which generates more
than one value
(e.g. heart sounds, a blood pressure taken lying and standing);
• a set of quantities constituting a single test
(e.g. a differential white cell count);
• a set of entries that might often be represented in a table
(e.g. auditory evoked potentials);
• a single healthcare action that had two or more purposes or
consequences.
battery in HL7
1/4
“battery:
a set of one or more observations
identified as by a single name and code number,
and treated as a shorthand unit
for ordering or retrieving results
of the constituent observations. …
Vital signs, electrolytes, routine admission tests, and
obstetrical ultrasound are all examples.
battery in HL7
2/4
"Vital signs (conventionally) consist of
diastolic and systolic blood pressure,
pulse, and respiratory rate.
Electrolytes usually consist of
Na+, K+, Cl-, and HCO3-.
Routine admission tests might contain
CBC, Electrolytes, SMA12, and Urinalysis.
(Note that the elements of a battery for our purposes
may also be batteries). "
battery in HL7
3/4
"Obstetrical ultrasound is a battery made up of
traditional component measurements and the impression,
all of which would be returned as separate results
when returned to the requestor.
A test involving waveform recording (such as an EKG)
can be represented as a battery made up of
results of many categories, including
digital waveform data, labels and annotations to the data,
measurements, and the impression. "
battery in HL7
4/4
"The word battery is used in this specification
synonymously with the word profile or panel.
The individual observation elements
within a battery may be
characteristic of a physiologic system
(e.g., liver function tests),
or many different physiologic systems.”
structure of a Template 1/2
GLOBAL INFORMATION
- global name of the template (with code)
- global interpretation or score
- global purpose / criterion for aggregation
- parent template (and kind of refinement)
- global circumstances for the template as a whole
(e.g. features of the sample, position of patient)
- either pre-defined (e.g. type of sample, device)
- or as slot to be instantiated (e.g. date of sampling)
- common parameters that apply to each member,
- either fixed (e.g. units) or variable
structure of a Template 2/2
INFORMATION ON MEMBERS of the template
(they can be other templates)
• complete name of member, with code
(from an agreed pre-existing coding system)
• value of the member (with units, if relevant)
• parameters that will assume a different value for
each member (e.g. time of sampling for each value
of a glucose tolerance test)
3-speed standard process
1. usual ballot in HL7
2. registration of data elements and CMETs
(and messages/docs) by Committee
3. registration of CMETs (and messages/docs) by
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national affiliates
government agencies
disease networks (e.g. cancer registries, ESRD)
member organisations
3 components of messages/docs
• data elements (+ definitions, value domains)
from RIM or from a data dictionary
• arrangements into a message/document
(+parsing rules and tools)
i.e. developed according to HMD
• "quality", i.e. adequacy to task
(all and only the needed data elements),
assured by ballot or registration