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Context-aware interactive use of SNOMED CT and terminology services in openEHR-based electronic health records

Daniel Karlsson, PhD, MSc

National Board of Health and Welfare, Sweden

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Erik Sundvall, PhD, MSc

Karolinska University Hospital, Karolinska Institute & Linköping University, Sweden

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Extra material & info: https://pen-pad-revival.github.io/

SNOMED CT and openEHR

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The future is already here — it's just not very evenly distributed

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William Gibson

What you will see is a revisit to the principles already shown in the early and mid 1990s by the PEN&PAD system and the following GALEN project.

PEN&PAD already then had better entry mechanisms than most current EHR Systems have now.

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A brief tour of Clinergy, based on PEN&PAD

Extra material & info: https://pen-pad-revival.github.io/

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Clinical care requires that patients be described rather than labelled.

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John Kirby & Alan Rector

PEN & PAD used a compositional approach combining features to describe patients, rather than picking from long lists of precoordinated terms.

The PEN&PAD data entry system: from prototype to practical system - PubMed (nih.gov)

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Note: laterality selection to select left or right arm.

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Note: NO laterality selection → prohibits “left nose”-nonsense etc.

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Recommended ingredients

Sample Title

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The “propeller” paper - ingredient categories

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Design experiences gained from �PEN & PAD, Clinergy, GALEN etc.�exty

Rector AL, Rogers J, Taweel A. �Models and inference methods for clinical systems: a principled approach. �Stud Health Technol Inform. 2004;107(Pt 1):79-83

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Ingredients in this demo

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  • SNOMED CT as terminology/ontology - www.snomed.org
  • SNOMED CT expression constraint language (ECL) to create different subselections of relevant �content in different parts of the form snomed.org/ecl
  • HL7 FHIR Terminology Service API as interface to a terminology server handling ECL. hl7.org/fhir/
  • openEHR for documentation models (called “archetypes” and templates) openehr.org
  • Better EHR Studio as a low/no-code environment “glue” to create �forms/applications based on openEHR templates and integrated with �logic and terminology server calls https://playground.better.care/studio/
  • In this demo we are not showing much of inference model, but there are�suitable decision support mechanisms etc. available in openEHR and/or FHIR

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openEHR context

Form builder

openEHR ”template”

For specific use case, e.g. local, regional or national.

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Free archetype and editing tool at https://tools.openehr.org/designer/

openEHR ”archetypes”

Clinical data models.

Found in internatioinal repository

https://ckm.openehr.org/ckm/

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Maximi-datasets, intended for many use cases. Multilingual

”Form renderer”

Web-component that can be included in any webapp. It displays forms and submits validated data to openEHR backends via standardized API.

Conditional logic

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FHIR Terminology Service API

  • Terminology-agnostic specification of terminology services
  • Can be used outside of the FHIR framework, e.g. with openEHR-based systems
  • Support for many SNOMED CT features
    • Hierarchies
    • Reference sets
    • Map Reference sets
    • Expression Constraint Language

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Expression Constraint Language

  • Expression Constraint Language (ECL) is a domain specific language for querying SNOMED CT
  • http://snomed.org/ecl

<<125605004 | Fracture of bone (disorder) |

All descendants of 125605004 | Fracture of bone (disorder) | and the concept itself (i.e. 125605004 | Fracture of bone (disorder) |)

12676007 | Fracture of radius (disorder) | . 363698007 | Finding site (attribute) |

The value of the 363698007 | Finding site (attribute) | attribute of the concept 12676007 | Fracture of radius (disorder) |, i.e. 62413002 | Bone structure of radius (body structure) |

<<62413002 |Bone structure of radius|:272741003 |Laterality|=<182353008 |Side|

All descendants of 62413002 | Bone structure of radius | which have a 272741003 | Laterality | which is a descendant of 182353008 | Side |

<<62413002 |Bone structure of radius|:[0..0]272741003 |Laterality|=<182353008 |Side|

All descendants of 62413002 | Bone structure of radius | which have exactly zero 272741003 | Laterality | which is a descendant of 182353008 | Side |

^723264001 | Lateralizable body structure reference set (foundation metadata concept) |

All members of the 723264001 | Lateralizable body structure reference set (foundation metadata concept) |

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FHIR and ECL walkthrough

Finding the fracture

…/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=ecl/<<125605004&count=10&displayLanguage=en&filter={filter}

    • <<125605004 | Fracture of bone |

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FHIR and ECL walkthrough

Finding the fractured bone

…/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=ecl/(<<({sctid}.363698007):[0..0]272741003=<182353008) AND ^734138000&count=10&displayLanguage=en

    • ( << ( {sctid} . 363698007 | Finding site | ):� [0..0] 272741003 | Laterality | = <182353008 | Side | ) AND�^734138000 | Anatomy structure and entire association reference set |

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12676007 | Fracture of radius (disorder) |

gives 62413002 | Bone structure of radius |, 313055005 | Epiphysis of radius |, 75129005 | Bone structure of distal radius |, …

but not e.g. 181940002 | Entire radius (body structure) |

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FHIR and ECL walkthrough

Finding out if it has a left and a right

…/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=ecl/{sctid} AND ^723264001&count=1

    • {sctid} AND ^723264001 | Lateralizable body structure reference set |

367591009 | Structure of bony part of nasal septum |

gives nothing as result

62413002 | Bone structure of radius |

gives 62413002 | Bone structure of radius | as result

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Conclusions

Having the right tools for the job…

terminology, information models, terminology services, no/low-code environments, …

building context-aware, interactive EHR templates with openEHR + SNOMED CT + FHIR Terminology Services is a piece of cake!

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https://pen-pad-revival.github.io/

Thank you for listening!

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Thanks to Better for providing free trial access to EHR Studio.�Thanks to Håkan Örman for providing remote login to a working Clinergy demo installation at Linköping University

Note (post-recording) errata available on next slide

Questions/End

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Errata

in the pre-recorded presentation Erik erroneously assumed and said they had access to thick heavy pen-computers. This is not correct, PEN&PAD was mainly used on stationary desk computers with keyboard and mouse.

(Images from Alan Rector)

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