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Clinical Model and Terminology Issues in Guideline Execution
Craig Parker, Harold Solbrig, Stan Huff & Roberto Rocha
as part of the SAGE project
The SAGE project is partially funded by NIST/ATP Cooperative Agreement Number 70NANB1H3049
SAGE Overview
Overview – Guideline Flow
GuidelineCreation Guideline
ImportGuidelineExecution
Create guidelinein terms of CEM
Perform mappings fromCEM to host database
Perform inferencebetween local instanceand CEM instance
Step 1
Step 2
Step 3
CEM = Clinical Expression Model (e.g. HL7 Templates)
A Guideline Example
Example drawn from ICSI Acute MI guideline.
Illustrates where clinical model and terminology actions will take place in the process of guideline development, deployment and execution.
Illustrates issues that may arise.
Creating Guidelines
Creating Guidelines
We want to say what to do if thepatient develops a new holosystolicapical murmur.
Lets represent this murmur usingHL7 template #12345 (ACMEmurmur).
In the vocabulary of this templatewe would say “pansystolic” insteadof “holosystolic”.
Step 1 – Guideline Creation
If the patient has a new holosystolic apical murmur then . . . (from ICSI Acute MI guideline)
The term “new holosystolic apical murmur” needs to be mapped to the CEM.
This could happen because at the time of creation only terms that are expressible in the CEM are available to the authors.More likely a knowledge engineer will have to determine a mapping from a clinicians words to the CEM.
We will leave the “new” part of the term for an exercise at a later time.
Step 1 – Map Guideline to CEM
If the patient has a newholosystolicapicalmurmur then . . .
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“MURMUR"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“PHASE"/> <value V=“Holosystolic"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“LOCATION"/> <value V=“Apical"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
CEM (HL7 Template)Guideline
Mapping Guideline to CEM
1) Map clinician’s words into a composite expression based on a reference terminology.
2) Use the resulting composite expression to create the CEM instance.
Map to a Reference Terminology
There are often many ways to say the same thing…
Murmur (finding) C0026806
Heart Problem (disease or syndrome) (C0795691)
Heart Murmur (sign or symptom) (C0018808)
Functional heart murmur (Finding) (C023255)
Heart murmur, functional and undiagnosed (Finding) (C0476259)
Systolic Heart Murmur, NOS (Finding) (C0232257)
Pansystolic murmur (Sign or Symptom) C0232258
Map the Guideline to a Reference Terminology
Mapping Granularity
Pansystolic murmur (Sign or Symptom) C0232258
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“?????"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“?????"/> <value V=“?????"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“?????"/> <value V=“?????"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
Map the Guideline to a Reference Terminology
Mapping Granularity
Pansystolic murmur (Sign or Symptom) C0232258
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“?????"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“?????"/> <value V=“?????"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“?????"/> <value V=“?????"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
?Granularity is too coarse
Map the Guideline to a Reference Terminology
Mapping Granularity
Murmur (finding) C026806 has-topography: Heart (Body part) C0018787 has-spatial-location: apical (C0205111) has-temporality: systolic (C00391555) quality: complete (C0205197)
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“C026806"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“Body Location"/> <value V=“C001878"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“temporality"/> <value V=“systolic"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
Sufficient Granularity
Map the Guideline to a Reference Terminology
Reference terminology must have a sound foundation
There still may be more than one way to say the same thing…
Pansystolic murmur (Sign or Symptom) C0232258 Murmur (finding) C026806
has-topography: Apex of heart (C0224811) has-temporality: systolic (C00391555) quality: complete (C0205197)
Map the Guideline to a Reference Terminology
Reference terminology must have a sound foundation
There still may be more than one way to say the same thing…
.. but you have to be able to determine whether they are the same thing.
Pansystolic murmur (Sign or Symptom) C0232258
Murmur (finding) C026806 has-topography: Apex of heart (C0224811) has-temporality: systolic (C00391555) quality: complete (C0205197)
Map the Guideline to a Reference Terminology
Software ToolsText search
Hierarchical and relationship navigation
Composition and decomposition
Map the Guideline to a Reference Terminology
Text search toolsSpelling correction
Mapping words and phrases to (near) synonyms; word stemming
Expanding and contracting acronyms and abbreviations
Multi-language capabilities
Context capabilities (MI = Myocardial Infarction? Mitral Insufficiency?)
NLP (“No family history of degenerative heart failure”)
Map the Guideline to a Reference Terminology
Hierarchy and relationship navigationSubtype navigation (broader and narrower terms)
Relationship traversal (etiology, has_part, …)
Search qualification
Map the Guideline to a Reference Terminology
Composition and DecompositionGreatest common supertype
Least common subtype
Convert to canonical form
Compare composite expressions
Difference composite expressions
Map the Guideline to a Reference Terminology
StandardsHL7 CTS Specification
Specifies basic text search tools
Does NOT cover lexical areas (spelling, acronyms, NLP)
Some relationship traversal
Limited composition/decomposition expressions
CTS Specification is directed at the current needs of HL7 (e.g. messaging).
A broader approach is needed to support guidelines.
Importing Guidelines
Importing GuidelinesThis new guideline uses HL7 template#12345.
We represent murmurs using our murmurtable.
How do we create a mapping?
Database Granularity
The same information can be carried in widely varying structures:
PT# observation
1110112 Heart murmur
PT# Tag Value
1110112 Observation Murmur
1110112 Location Heart
PT# Heart Murmur
1110112 TRUE
PT#
1110112
Table 17: Patients with Heart Murmur
Table Names
Tag/Value Pairs
Column Headings
A code in a table
Database Names
Free text
PT# observation
1110112 “Findings indicate a pronounced apical murmur throughout the entire systolic phase…”
Heart MurmurClinic
Database Granularity
The same information can vary in granularity
Slots must be composed or decomposed in the mapping process.
The database may vary in the amount of detail
Some slots may not have mappings.
Step 2 – Guideline Import
Make mapping from CEM to host database.Database Record: HeartMurmurObservation Type = Mitral Regurgitation Grade = III/VI Location = 5th Intercostal Space . . .
Have to deal with issues of differing slots and differing granularity of slotsStructural decompositionSet up inference hierarchies
Step 2 – Map Database to CEM
HeartMurmurObservation Type = Mitral Regurgitation Grade = III/VI Location = 5th intercostal space …
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“MURMUR"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“PHASE"/> <value V=“Pansystolic"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“LOCATION"/> <value V=“5th Intercostal Space"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
CEM (HL7 Template)
Database Instance
When populating the CEMthe type “Mitral Regurgitation”
is mapped to phase “Pansystolic”
Guideline Execution
Guideline Execution
The guideline says that if the patienthas a new apical pansystolic murmurwe should . . .
Looking in my database I find that thepatient has a new murmur at the 5th intercostal space.
Is the 5th intercostal space an apicallocation?
Step 3 – Guideline Execution
Traverse term-to-CEM map (depending on compilation strategy).
Traverse CEM-to-DB map.
Perform “MLM” logic.Do terminology inference.
Guideline Execution
Guidelines use two information sourcesTriggers – new information being entered into the system
Existing data – information already contained within the database
Guideline Execution
Approach is different for each:Triggers
Need to determine whether the new information represents an instance of the guideline triggerAnswer may be “yes”, “no”, or “need more information”
DatabaseNeed to select information that may satisfy guideline criteriaDetail, granularity and logic usually precludes exact selectionHave to maintain a balance between quantity (select * from dx_table where pt=‘1110112’) and complexity (select * from dx_table, … where dx_code in (a,b,c,d,…) or dx_code in (select * from codedTerm where sourceCode=‘a’ and relcode in (1,2,3))
Step 3 - Perform Logic
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“MURMUR"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“PHASE"/> <value V=“Pansystolic"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“LOCATION"/> <value V=“Apical"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
Guideline CEM Instance<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“MURMUR"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“PHASE"/> <value V=“Pansystolic"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“LOCATION"/> <value V=“5th Intercostal Space"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
Database CEM Instance
Apical LocationApical Location
55thth ICS ICS 66thth ICS ICS ……
…… …………
Inference from Terminology
Apical has-child 5th ICSApical has-child 6th ICSApical has-child …
Database representation of a Semantic Network
Other Execution Questions
Where do we iterate through the database instances?
Database services?
Guideline logic (e.g. Arden or GELLO)?
How are terminology services used?Standard terminology services
Host specific terminology services
Notes on Templates
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“Pansystolic murmur"/></A_Observation_event>
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“MURMUR"/> <AR_Observation_event_component> <type_cd V="COMP"/> <A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“PHASE"/> <value V=“Systolic"/> </A_Observation_event> </AR_Observation_event_component> <AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“LOCATION"/> <value V=“Apical"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
<A_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“Systolic Heart MURMUR"/><AR_Observation_event_component> <type_cd V="COMP"/> <AR_Observation_event> <class_cd V="OBS"/> <mood_cd V="EVN"/> <cd V=“LOCATION"/> <value V=“Apical"/> </AR_Observation_event> </AR_Observation_event_component> . . .</A_Observation_event>
Notes on Templates
Need to evolve in tandem with terminologies
Heart Murmur ObservationApical HeartMurmur Observation
– Systolic Apical Heart Murmur Observation
• Holosystolic Apical Heart Murmur Observation
Need to be named, cataloged, cross referenced and formally organized
Notes on Templates
To be portable, templates have to be based on an underlying reference terminology as well
Templates represent clinical statements
Without a thorough understanding of the statements and their hierarchical nature, it quickly becomes virtually impossible to make reasonable guidelines.