Using realist ontology to link patient records with terminologies

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Using realist ontology to link patient records
with terminologies

• Dr. W. Ceusters
• European Centre for Ontological Research
• University of Saarbrücken

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Affiliations and Partners
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Management
Strategic Management Board
Advisory Board
Directors
Representatives of affiliates
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Interoperability of electronic health records

• By end 2006, Member States, in collaboration
  with the European Commission, should identify and
  outline interoperability standards for health
  data messages and electronic health records,
  taking into account best practices and relevant
  standardisation efforts.
• Achieving a seamless exchange of health
  information across Europe requires common
  structures and ontologies of the information
  transferred between health information systems.

e-Health - making healthcare better for European
citizens An action plan for a European e-Health
Area COM (2004) 356 final, 30.4.2004, p17
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Ontology

• An ontology defines the terms used to describe
  and represent an area of knowledge, and are used
  by people, databases, and applications that need
  to share domain information (a domain is a
  specific subject area, such as health or
  medicine).

e-Health - making healthcare better for European
citizens An action plan for a European e-Health
Area COM (2004) 356 final, 30.4.2004, p17
OWL Web Ontology Language Use Cases and
Requirements W3C Recommendation 10 February 2004

http//www.w3.org/TR/webont-req/
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Ontology

• Ontologies need to specify descriptions for the
  following kinds of concepts
• Classes (general things) in the many domains of
  interest
• The relationships that can exist among things
• The properties (or attributes) those things may
  have

OWL Web Ontology Language Use Cases and
Requirements W3C Recommendation 10 February 2004

http//www.w3.org/TR/webont-req/
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Focus of this presentation

• Ontology DOES HAVE a role in maximizing the
  potential uses of the EHCR
• by making the contents understandable both for
  humans and machines in the same way
• Allows us to identify mistakes in current systems
• gives us a methodology to do better
• But only on the condition that the RIGHT
  SORT of ontology is used

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Understanding content (1)
We see
John Doe has a pyogenic granuloma of the left
thumb
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Understanding content (2)
The XML misunderstanding
We see
ltrecordgt ltpatientgtJohn Doelt/patientgt ltdiagnosisgtpy
ogenic granuloma of the left thumblt/diagnosisgt lt/r
ecordgt
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Understanding content (3)
lt129465004gt lt116154003gt John Doe lt/116154003gt lt
8319008 gt 17372009 ltfinding sitegt 76505004
ltlateralitygt7771000lt/lateralitygt lt/finding
sitegt lt/ 8319008 gt lt/129465004gt
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The view of terminology

• In Information Science
• An ontology is a description (like a formal
  specification of a program) of the concepts and
  relationships that can exist for an agent or a
  community of agents.
• In Philosophy
• Ontology is the science of what is, of the kinds
  and structures of objects, properties, events,
  processes and relations in every area of reality.

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Summary of current deficiencies in traditional
and formal terminologiesbased on the concept
paradigm

• Terms often require reading in context
• ICD stomach for tumor in stomach
• Agrammatical constructions
• Several systems Hepatitis, acute
• Semantic drift as one moves between hierarchies
• UMLS fever ISA clinical exam ISA measurement ISA
  data collection ISA information science
• labels for terms do not correspond with intended
  meaning
• SNOMED-CT leg for lower limb or lower leg
• underspecification (leading to erroneous
  classification in DL-based systems)
• overspecification (leading to wrong assumptions
  with respect to instances)

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An underspecification example
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Current EHCR architecturesand message
standardsare not any better !

1. They refer to such terminologies for most of the
   content
2. Their structures are built using the same
   error-prone approach

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CENs starting position for ENV13606 is ok
CEN ENV 13606

• The real world of health and health care is made
  up of individual clinical situations
• (of which the participants are called associate
  topics), that are described by an EHCR author as
  clinical statements.
• Within an EHCR system each clinical statement
  will be expressed as an elementary healthcare
  record entry.

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CENs view on EHCR and reality
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Architectural Component Attributes
CEN ENV 13606
Refer to situations and statements and rely on
terminology
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KMEHR-message
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KMEHR element dayperiod/cd

•  
• afterbreakfast  afterdinner  evening
• afterlunch  afterlunch  morning
• afternoon  beforebreakfast  night
• beforedinner  beforelunch 
• betweenbreakfastandlunch 
• betweendinnerandsleep 
• betweenlunchanddinner 
• betweenmeals     thehourofsleep

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KMEHR element duration

•  unit enumeration
• vv  wv  ww  1 000/mm3
• mg/dl  amp  bag  bol 
• bot  box  c  can 
• cap  cc  cm  cmm
• cnt  ctr  daily  day 
• dis  drm  fl  fld 
• ...

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Patient sex

• male
• female
• Unknown ???

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From Speech Acts to Information Model
HL7-RIM
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HL7 Acts contains
A collection of classes including the Act class
and its specializations. These relate to the
actions and events that constitute health care
services.
Account ActRelationship ControlAct
DeviceTask DiagnosticImage FinancialContract
FinancialTransaction InvoiceElement
ManagedParticipation Observation Participation
PatientEncounter Procedure PublicHealthCase
SubstanceAdministration Supply WorkingList
Diet Act
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HL7 Acts contains
A collection of classes including the Act class
and its specializations. These relate to the
actions and events that constitute health care
services.

• Account ActRelationship
• ControlAct DeviceTask
• DiagnosticImage FinancialContract
• FinancialTransaction InvoiceElement
• ManagedParticipation Observation
• Participation PatientEncounter
• Procedure PublicHealthCase
• SubstanceAdministration Supply
• WorkingList Diet
• Act

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Messy hierarchy
Acts A collection of classes including the Act
class and its specializations. These relate to
the actions and events that constitute health
care services.
Act A record of something that is being done,
has been done, can be done, or is intended or
requested to be done
Financial contract A contract whose value is
measured in monetary terms. Examples Insurance
Purchase agreement
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My use of the word ontology,or what we really
need

• a representation of REALITY that is
  understandable for a computer and reflects the
  properties of the objects within its domain in
  such a way that there obtain substantial and
  systematic correlations between reality and the
  ontology itself.

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A look in the operating theatre
A lot of objects present
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A look in the operating theatre
A lot of processes going on
Haydom Lutheran Hospital, Tanzania
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Axiom

• If the picture is not a fake, we (i.e., me and
  this audience) KNOW that that hand, that surgeon,
  ... EXISTED, i.e. WERE REAL.
• But importantly that hand, surgeon, kocher,
  mask, ... EXISTED independently of our knowledge
  about them and also the part-relationship
  between that hand and that surgeon, and the
  processes going on, were equally real.

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The blurr of possible worlds
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Axiom

• Concept-based terminology (and standardisation
  thereof) is there as a mechanism to improve
  understanding of messages by humans.
• It is NOT the right device
• to explain why reality is what it is, how it is
  organised, etc., (although it is needed to allow
  communication),
• to reason about reality,
• to make machines understand what is real,
• to integrate across different views, languages,
  conceptualisations, ...

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Why not ?

• Does not take care of universals and particulars
  appropriately
• Concepts not necessarily correspond to something
  that (will) exist(ed)
• Sorcerer, unicorn, leprechaun, ...
• Definitions set the conditions under which terms
  may be used, and may not be abused as conditions
  an entity must satisfy to be what it is
• Language can make strings of words look as if it
  were terms
• Middle lobe of left lung
• ...

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Ontology versusDescription Logics

• In the Description Logic world
• terms and definitions come first,
• the job is to validate them and reason with them
  by means of a model
• but whether the model correspond to reality is
  not its problem (Workshop on DL, Saarbrücken,
  22-23/11/2004)
• In the realist ontology world
• robust ontology (with all its reasoning power)
  comes first
• terms, term-hierarchies and record architectures
  must be subjected to the constraints of
  ontological coherence

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(Simplified) Logic of classes

• primitive
• entities particulars versus universals
• relation inst such that
• all classes are universals all instances are
  particulars
• some particulars are not instances e.g. some
  mereological sums
• subsumption defined resorting to instances

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What is our message ?

• From Good Characteristics of a EHCR (Eurorec
  1997, Paris) to Good characteristics of an
  Ontology
• Crucial how does an ontology relate to reality
• Pragmatism is no excuse for sloppiness
• Philosophical is no synonym for useless
• Subject EHCR standards that deal with semantics
  to a sound ontological analysis
• EHCR is an ideal domain, because it deals with
  real patients in real situations.
• When building models, they should be related to
  reality in the right way