Clinical templates, registries and terminologies

1
Clinical templates, registries and terminologies

• Angelo Rossi Mori
• National Research Council, Rome - Italy
• HL7 / Clinical Templates SIG CEN / TC251 / WG II

2
Contents

• what is a clinical template ?
• batteries, data sets,
• reusable fragments of messages
• 3 pillars for semantic interoperability
• repositories, templates, value domains
• HL7 light a complementary approach
• decentralisation of a registration process
• involvement of professionals and agencies
• a common strategy for HL7 and CEN ?

3
what is a template ?

• too many legitimate
• perspectives and options

4
battery in HL7 1/5

• 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.

5
battery in HL7 2/5

• "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). "

6
battery in HL7 3/5

• "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. "

7
battery in HL7 4/5

• "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. "

8
battery in HL7 5/5

• "The word battery is used in this specification
• synonymously with the words 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.

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Crucial issues

• Version 2.x provides no rules for harmonization
  / registration of batteries
• Constituent elements of a batterymust be
  predefined
• Need for a registry of data elements
• Need for computable value domains(numeric
  ranges, code sets)

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Example on Lab Data results

• from HL7 version 2, 7.4.3
• OBR1870930010OECM3562LAB 80004ELECTROLYTES
  
• OBX1ST84295NA150mmol/l136-148...
• OBX2ST84132K4.5mmol/l3.5-5...
• OBX3ST82435CL102mmol/l94-105...
• OBX4ST82374CO227mmol/l24-31

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Option 1 master tables

• the content of the "electrolytes template
• is a set of 4 OBXs
• with locally predefined names and units.
• For example, stored in Master Tables
• Only the template name is sent in the order
• Numeric values
• will be filled in at the instantiation
• How can we harmonize definitions
• across master tables of different organizations ?

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negotiating the template

• the master table approach involves
• a negotiation between sender and receiver
• they exchange the definition of template,
• they refine it
• - how to assure version identification ?
• - is it safe to send only the template name in an
  order, without the detail on content ?

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NEW panel names in LOINC

• from LOINC, vers. June 2000, at
  www.regenstrief.org/loinc
• hemogram panel (code24358-4)
• panel elements erythrocytes leukocytes
  hematocrit hemoglobin MCV MCH MCHC RDW
• hemogram platelets panel (code24317-0)
• panel elements hemogram panel platelets
  MPV

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option 2 LOINC as register

• first 51 panels are available
• fast and reactive maintenance process
• LOINC could be a good source for names and codes
  of templates
• but description of content is text-based, i.e.
• ranges are not computer-processable
• value sets do not use LOINC codes
• is the description defining the template ?
• which change justifies a new template ?

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Example on Medical Record in HL7

• from HL7 version 2, 9.6
• TXA0001HPhistory physicalTXtext
• OBX1CE2000.40CHIEF COMPLAINT ...
• OBX2ST2000.01SOURCEPATIENT ...
• OBX3TX2000.02PRESENT ILLNESS SUDDEN ONSET
  OF CHEST PAIN. 2 DAYS, PTA ASSOCIATED WITH
  NAUSEA, VOMITING SOB. NO RELIEF WITH ANTACIDS

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option 3 set of detailed standards

• CHIEF COMPLAINT
• SOURCE
• PRESENT ILLNESS
• how to obtain wide consensus
• on section of documents ?
• see standardization initiatives in
• ASTM 31.25 and
• Clinical Doc. Architecture level 2 (PRA)

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Systematic rules for composition

• Template systolic blood pressure
• OBX for systolic BP
• qualifiers
• patient's position
• device
• measurement site
• the circumstances of the measurement could be
• additional OBXs
• coded elements in a compositional data type
• detail within a molecular code

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option 4 combinatorial codes

• the observation code for systolic BP can be
  either
• a single molecular code or a combination of
  codes on
• patient's position
• device
• measurement site
• We must control the overlap between
• terminological component of observation code
• explicit RIM attributes
• (rules for combinatorial codes
• are managed by coding system developers)

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recurring subsegments

• from ENV 12610, Medicinal product
  identification,
• Table 5.2.2 Trade medicinal product
  identifiers
• clinical template
• trade trade unique
• contents group name trade ID
• 4.2.1 medicinal product
• designation x x x
• 4.2.8 dosage form x x
• 4.2.14 route of administration x x
• 4.2.6 strength x x
• 4.2.11 medicinal product
• batch number x

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option 5 RMIM - CMET

• define new (local) templates
• applying the same development methodology
• conceived for standard messages in HL7
• need for thousands of data elements
• as (local) extensions of the RIM
• need for a registry of templates ?

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Schemas (e.g. BizTalk)

• from the iEHR schema, by iSoft, at
  www.biztalk.org
• ltElementType name"QuantifiableObs gt
• ltelement type"MeasurableQuantity"/gt
• ltelement type"ResultAsNumber"/gt
• ltelement type"ResultAsRange"/gt
• ltelement type"ResultAsDate"/gt
• ltelement type"ResultAsText"/gt
• ltelement type"ReferenceLimit"/gt
• lt/ElementTypegt

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option 6 XML family

• define XML labels
• define their combination by measures external
  to HL7 constructs (e.g. XML schemas ?)
• in Biztalk (not limited to healthcare)
• meaning of labels and value sets are not
  described !
• no comparison of XML tags from different vendors
  !
• in ebXML (not limited to healthcare)
• registries ?
• a specific HL7 registry with XML.org ?

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Conditional templates 1/3

• from the CDC form for Hepatitis A notification
• BASIS FOR DIAGNOSIS
• CLINICAL DATA
• Symptomatic ? ?yes ?no ?unknown
• if yes, Onset date ____
• Diarrhea ?yes ?no
• if yes, from ____ to ____
• Jaundiced ?yes ?no
• Hospitalized ?yes ?no
• Died ?yes ?no
• LABORATORY TESTS ...

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Conditional templates 2/3

• Diarrhea ?yes ?no if yes, from ___ to
  ___
• Diarrhea is a finding, with boolean values.
• The above structure could be generalised as
• Template boolean finding with dates
• booleanFindingLOINCcode booleanValue
• if booleanValue yes
• starting dateLOINC2345-7 date
• ending dateLOINC3456-8 date

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Conditional templates 3/3

• Template boolean finding with dates
• booleanFindingLOINCcode booleanValue
• if booleanValue ...
• Refinement of template
• conditional block diarrhea with dates
• diarrheaLOINC1234-6 booleanValue
• if booleanValue yes
• starting dateLOINC2345-7 date
• ending dateLOINC3456-8 date

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option 7 Arden syntax

• Arden syntax is the existing mechanism
• for if-then rules
• it is harmonized with RIM and HDF
• it could be extended for this purpose
• (a special mechanism
• just for this kind of template )

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Clinical check list ? ( DICOM )

• from Nomenclature of Digestive Endoscopy, OMED
  1994
• template name description of duodenoscopy
• data elements value domain (for duodenoscopy)
• lumen normal, spasm, stenosis,
• contents blood, biliary stones, parasites,
• wall rigid, decreased distensibility,
• mucosa atrophic, granular, hyperemic,
• hemorrhage mucosal bleeding, varices,
• flat lesions aphta, infiltration,
• protrusions papule, polyp,
• ...

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Legal data sets ?

• from the Belgian law of 14.08.1987
• template name data items for nursing file
• data elements
• 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
• ...

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
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option 8 Z segments

• Where is the limit ?
• Why clinical templates cannot extend to whole
  messages and Z-segments ?
• Registration and harmonisation
• appropriate control by HL7
• over the Z-segments
• (and over the list of allowed data elements)
• large benefits to the whole HL7 community

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why templates ?

• purposes and use cases

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typology of templates 1/2

• USAM tables
• e.g. role-link-role
• ENCAPSULATION (terminology vs RIM)
• e.g. to describe style in messages
• BATTERY set of Acts
• sets of observations (i.e. battery)
• (precise description for orders and payments)
• goals, outcomes
• sets of procedures (e.g. clinical guidelines)
• data sets (e.g. from regulatory agencies)

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typology of templates 2/2

• CDA-L2 set of sections
• Clinical Document Architecture - level 2
• expected shape of a document
• DICOM SR set of sections, acts, materials,
  devices,
• MESSAGES profiles, new messages ?
• internal needs of an organization
• needs of a specialty (e.g. cancer network)
• needs of agencies (e.g. Public Health reporting)
• needs of a region / country (e.g. xDT Germany)

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Expressing constraints on the RIM

• from Usam manual, version 2.6, May 2000 (table
  17)
• template action with admitted relationships
• action
• has precondition
• precondition in criteria mood
• has trigger
• trigger in criteria mood
• has contraindication
• contraindication

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Style guidelines

• a) Representation using Value Name style
• name is generic, values are elements of a list
• HLA Antigen found Aw43, B27, Cw1, Dw12, ...
• b) Representation using Variable Name style
• list of all names, values are boolean
• HLA Aw43 Antigen Present, Absent
• HLA B27 Antigen Present, Absent
• Both styles are in use which one should be
  preferred ?
• clinical templates guidelines for style ?

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guidelines of practice

• define local or common practice rules
• example from HL7 v2.x
• Routine admission tests might contain
• CBC,
• Electrolytes
• SMA12
• Urinalysis
• (Note that the elements of a battery for
  our purposes may also be batteries).

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NO - automatic filling in of defaults

• from The Berkshire Eagle, May 23, 2000
• template normal liver
• A GP was discovered to use templates
• for the most frequent normal situations ,
• to automatically fill in
• a list of detailed default values
• as if he was actually making
• each individual observation
• this is not our meaning of clinical template

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cluster in ENV 13606

• CLUSTER "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.
• (cont.)

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cluster in ENV 13606

• 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.

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weak vs strong templates

• weak templates (organisers)
• to organize information
• e.g. subsections of a clinical document
• see also headed sections
• in ENV 13606 (EHCR - healthcare record)
• strong templates (bundles)
• to handle reusable aggregations
• e.g set of structured data elements
• see also clusters in ENV 13606

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organisers

• Organisers are defined by their name only.
• They contain at least one organiser or one
  textual data element (and bundles)
• Organisers provide a weak context to their
  content.They provoke expectations in the human
  users.They convey authors perspective on data.
• The expected content of an organiser (e.g. the
  internal structure of a document)may be
  predefined to guide users

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bundles

• Bundles are defined by their content.They
  identify a set of closely related items
• with a bottom-up process.They represent
  complex conceptual units.
• They contain only bundles and/or structured
  data elements (i.e. coded or quantitative data
  elements).
• Bundles provide a strong context to their
  content.They set a scope for their components.
• Clusters are usually predefined.

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bundle
organiser
structured item name range
textual item name text
quantitative item name interval with units
coded item name value domain
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sharing templates

• need for registries ?

44
emerging needs in HL7 ?

• refine standard messages and documents with
  local detailed constraints or refinements,
  e.g. to satisfy the needs of
• sub-communities (diabetes, cancer, ESRD)
• ad-hoc information flows (e.g. CDC, HCFA)
• regional or national information flows
• management of pathology networks
• registries, clinical trials, sharing records
• secondary uses
• reporting to authorities, statistics

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clinical templates a real need ?

• is there a need to reduce combinatorial
  alternatives and impose a common style ?
• what is better achieved by
• a-posteriori transformations ?
• is there a need for control over the
  processthrough registration and support
  databases ?
• (i.e. decentralise but avoid the chaos)
• if communication is local, why HL7 should
• introduce international rules or registries ?

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my vision need for registries

• if we want to share clinical templates
• across organizations,
• components of templates must be registered.
• all names and labels used in templates
• should be stored in a registry
• should be mapped to the RIM classes
• should have a well defined value set
• (how can we decentralize the register ?)

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3 pillars for real interoperability

• The optimal strategy is based on 3 pillars
• 1. data dictionaries and metadata registries,
• including appropriate LOINC codes
• 2. clinical templates
• 3. tables with enumerated value domains
• they are complementary
• all 3 pillars are needed to assure a real
  semantic interoperability

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1. Metadata registries 1/2

• A registry of data elements, between
• one thousand robust data elements i.e. the
  attributes in the RIM
• millions of user-created XML labels
• Specializations 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

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1. Metadata registries 2/2

• Quick solution
• Collection of data sets and lists of XML tags
• with either answer-list or ranges of values
• (e.g. see names for observations in LOINC
• see also xDT/Germany, ASTM E1384)
• Optimal solution
• Integrated repository (e.g. ISO 11179)
• with uniform and comparative representation
• of data elements from all the sources

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2. Clinical templates

• to aggregate data elements from the repository
• (including the RIM) into meaningful fragments
• i.e. building blocks, from predefined data
  elements,
• to produce more detailed messages, between
• hundreds of balloted standard messages
• millions of user-created DTD/schemas
• Templates (and the related data elements)
• need a process for (local) registration
• under the control of HL7 TCs
• a neutral language to represent templates ?

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3. Value domains

• Thousands of explicit tables
• with enumerated value domains
• or numeric ranges
• admitted values for each data element
• in the context of a clinical template
• "terminologies in context"
• coordinated by HL7 vocabulary TC
• (see the context groups in DICOM-SR)

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HL7 light ?Open HL7 ?

• a registration process
• in addition to normal ballots

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HL7 light ?

• fix by ballot the common framework (ISO ?), i.e.
• basic rules and development processes
• RIM and common templates
• rules for registration
• my vision two different speeds legacy
• ballot the general standards (as usual)
• control decentralisation of detail
• a registration process driven by HL7 users
• 3. legacy systems (Z-segment and adaptations)

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1. Unified development process

• Uniform process, according to HDF (HL7, CEN)
• the development framework allows to define
• the standard for a type of messages/documents
• uniform measures for a vendor (level 7 !) to
  create, transport, parse, and visualizethe
  instances of messages and documents
• general methods
• same software
• common skills
• basic manuals and training

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2. Sharing pre-defined building blocks

• 1. usual ballots in HL7 (RIM, messages, CMETs)
• the RIM (and the CEN-RIM)
• general-purpose messages
• basic clinical templates and CMETs
• 2. HL7 Committees register data elements and
  shared clinical templates (LOINC ?)
• data elements registered wrt the RIM
• related value domains
• useful clinical templates

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( Not just a list )

• harmonise data elements / XML tags across
  different systems/organisations
• facilitate users feedback into the process by
  uniform collection of legacy usages
• facilitate mapping from legacy data elements of
  end-users to registered data elements
  similarly to RELMA for LOINC

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3. Decentralise detailed content

• HL7 members register "local" clinical templates
• define the content of their typical messages and
  documents (i.e. all and only the detailed data
  elements needed and adequate for a task)
• National affiliates (and CEN/TC251 ?)
• US government agencies
• disease networks (e.g. cancer registries, ESRD)
• member organisations
• professional bodies

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the new SIG

• a forum for discussion
• and harmonization

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A new SIG on Clinical Templates

• to coordinate discussion across TC/SIGs
• and with external bodies
• CEN, ASTM, DICOM, GEHR.org, ...
• XML schemas, bizTalk, ebXML,
• compare perspectives on
• real needs
• use cases, purposes, target groups
• potential solutions
• no production activities within the template SIG

60
which HL7 group is involved ? 1/3

• most HL7 groups are already dealing
• with some template-like ideas.
• In my understanding
• Modeling and Methodology (generalisation of the
  HL7 Development Framework)
• Government Projects SIG (data sets and messages
  controlled by Agencies, e.g. HCFA and CDC)
• (cont.)

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which HL7 group is involved ? 2/3

• Image Management SIG (see DICOM Templates)
• Orders and Observation TC (formalisation of
  constraints described by narrative in the USAM
  document, aggregates of entries as batteries)
• Patient Care TC (definition of clinically
  meaningful aggregates, e.g. goals)
• (cont.)

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which HL7 group is involved ? 3/3

• Clinical Decision Support and Arden Syntax TC
  (protocols and structures for decision making)
• Structured Document TC (organisers and
  structured containers)
• XML SIG (relation with XML schemas, registries
  of XML labels)
• Vocabulary TC (overlap with compositional
  systems, tables of value domains)

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a forum for discussion 1/2

• Which mechanism can remain local ?
• Which mechanism should be regulated ?
• Is order of components relevant ?
• And relationships among components ?
• Registration process or balloting ?
• who will manage the register ?
• what should be centralized ?
• How to include clinical templates
• in the whole HDF development framework ?

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a forum for discussion 2/2

• how do we ensure that a registered template is
  unique ?
• how do we manage the process ofcreation, review,
  and approval ?
• what about customization/adaptations ?
• how can we support concurrentcontent developers
  ?
• how can we coordinate acrossdifferent
  professional groupsthat may want to participate ?

65
role of HL7 groups vs templates SIG

• The SIG is made of members from other groups
• each TC/SIG should produce its vision
• real user needs, use cases, kind of templates,
• examples and the future production activities.
• Role of the new SIG
• clarify the perspective of each group
• discover similarities and differences
• comparative review of TCs visions
• strategic proposals to the HL7 Board

66
who has a real need for templates ?

• e.g. professional societies
• (see cardiologists in DICOM )
• quality of reports (check list)
• (complete, understandable, processable)
• clinical databases
• uniform data collection
• (clinical trials, clinical registries)
• are they aware ?
• what is the limit of promotion ?

67
perceived by professional groups ?

• groups that are currently working
• on clinical data sets include
• DEEDS (CDC)
• Am. Dental Association
• Am. Ophtalmology Association
• Am. Coll. Obstetrics and Gynecology
• Am. College of Pediatrics
• (consistent structure across specialties
• would be in the best interest of medicine)

68
filling in the gap

• clinical templates as a keyword
• everything filling in the gap between
• (slow) ballot-based process
• Z-segments and local adaptations
• including registry of data elements (LOINC)
• and related vocabularies
• now that XML is available
• we dont need HL7 anymore, right ?

69
Issues

• what is a clinical template ?
• batteries, reusable fragments of messages,
• data sets, messages,
• internal structure of documents
• 3 pillars for semantic interoperability
• repositories, templates, value domains
• HL7 light ?
• decentralisation of a registration process
• neutral representation of templates
• involvement of professionals and agencies
• concrete needs, use cases, solutions
• volunteers to prepare the January meeting