LOINC and SNOMED CT

David MarkwellHead of Implementation and EducationInternational Health Terminology Standards Development Organisation

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Enabling SNOMED CT and LOINCto work togetherDavid MarkwellHead of Implementation and EducationIncludes material developed by Farzaneh Ashrafi and Suzanne Santamaria

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Agreement completed

▪ Announcement 24 July 2013▪ Joint IHTSDO and RII press release: 

▪ www.ihtsdo.org/loinc/press_release.pdf▪ Full text of the agreement: 

▪ www.ihtsdo.org/loinc/agreement.pdf▪ The same materials are also on the LOINC site

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Objectives of the agreement

▪ To support consistent coding of order entry and result reporting

▪ by addressing coding and modeling of terminology content in the domains covered by LOINC orders and observations

▪ To avoid unnecessary duplication of effort▪ To develop cooperation between IHTSDO & Regenstrief

Not a one-off activityNot an acquisition or mergerNot an exclusive arrangementA long-term working relationship

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The practical approach

▪ Maps between LOINC Parts and SNOMED CT▪ Addition of content where necessary to complete these maps

▪ LOINC terms linked to “SNOMED CT Expressions” to provide SNOMED CT semantic view of LOINC Terms

▪ Limited additions of content subject to specific restrictions intended to limit duplication of effort and content

▪ Greater consistency in coding of order entry and results reporting

▪ Improvements in each terminology▪ Improved analytics and quality control

▪ Query LOINC via SNOMED hierarchy and relationships▪ Better identification and maintenance of laboratory tests value

sets for public health reporting▪ Enhanced tracking and management of infectious disease

outbreaks▪ Integrates disparate elements in EHRs

▪ Lab test in LOINC with elements in patient chart in SNOMED (e.g. allergies, chief complaint, vital signs, age)

▪ Enables clinical decision support, may aid in reimbursement

Value

▪ Internal project team – currently 6 individuals▪ Head of Terminology, Head of Content Development, Head of

Implementation and Education, Head of Delivery, Terminologists▪ LOINC project team contact▪ Executive Policy Group (3 from RII and 3 from IHTSDO)▪ Observable and Investigation Model Project

▪ Subproject on CollabNet (those interested in participating contact SSA or FAS)

▪ Project groups (Substance Redesign; Organisms; Microbiology)

▪ External collaborators:▪ US Veterans Administration▪ Kaiser Permanente

▪ IHTSDO Content Committee:▪ Guidance, coordination with other IHTSDO initiatives

▪ Contractors: ▪ Developing implementation guidance: BITAC

Roles of individuals and groups

▪ Scope▪ Laboratory LOINC▪ Vital signs▪ Physiologic measurements▪ Anthropomorphic measurements and evaluations

▪ Phases▪ Initial

▪ Top 2000 lab LOINC tests▪ Microbiology▪ Chemistry▪ Vital signs

▪ Subsequent▪ Remainder of lab LOINC▪ Measurements

Project scope

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Preview releaseCandidate baseline

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Alpha release

July 2015November 2014

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Meeting

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Meeting

1. Collaborationa. Invite participation by stakeholdersb. Regular meetings (internal group; EPG; KP)c. Ensure approach works with other concurrent design projects (e.g.

Substance Redesign)d. Publicize work and progress

2. Content developmenta. Add and update content to SNOMED to complete the LOINC Parts

map (techniques, substances, etc.)b. Determine the best approach for handling complex concepts c. Create documentation of process and outcomes d. Create and deliver alpha release and Technology Preview

3. Test and obtain feedbacka. Document and test the Observables model (including description logic) b. Document the quality test planc. Review feedback on releases from stakeholders

Development phase objectives

1. Collaborationa. IPaLM SIG, internal project groups (e.g. Substance Redesign)

engagedb. Regular meetings held (internal group; EPG; KP)c. Posters at ICBO and SNOMED CT Showcase this Fall

2. Content developmenta. SNOMED concepts added for LOINC Part mapping, metadata, etc.b. Draft implementation guidance released July 2014c. alpha release released May 2014 with documentation

a. 117 LOINC Termsd. Development of Technology Preview Structure Processe. Technology Preview released October 2014 with documentation

a. 2100 LOINC Parts in LOINC Part to SNOMED RefSetb. 9700 LOINC Terms in LOINC Term to Expression RefSet

Development phase progress

3. Test and obtain feedbacka. Report on implementation horizon and scope released April

2014b. Documented and tested the Observables model (including

description logic and creation of OWL ontology) c. Performed quality test plan for functionality and reproducibilityd. Analyzed feedback on alpha prototype and modified content

Development phase progress continued

▪ Prototype: Released in May 2014▪ Initial Technology Preview: Released in October

2014▪ Repeat of Technology Preview: Scheduled for

March 2015▪ Candidate baseline: Scheduled for July 2015▪ Actual baseline: TBD (July 2015 release becomes

baseline if no changes needed)

Summary of sequence for content development and release

Proposed release formats (1)LOINC Parts to/from SNOMED CT – LOINC Map Refset file

Field Data type Purpose

id UUID A 128 bit unsigned integer, uniquely identifying the reference set member.

effectiveTime Time Specifies the inclusive date at which this change becomes effective.

active Boolean Specifies whether the member's state was active or inactive from the nominal release date specified by the effectiveTime field.

moduleId SCTID Identifies the member version's module. Set to a child of |Module| within the metadata hierarchy.

refsetId SCTID Identifies the reference set.

referencedComponentId SCTID A reference to the SNOMED CT concept being mapped to/from the LOINC Part Code.

mapTarget String The value of the LOINC Part Code to which the concept is mapped.

attributeId SCTID SNOMED CT concept representing the attribute to which the referencedComponentId applies. Usually derived from the LOINC Part Type.

correlationId SCTID The correlation between the SNOMED CT concept and the LOINC Part Code. Subtypes of 447247004 | SNOMED CT source code to target map code correlation value|

• Exact match, Broad (SNOMED CT) to narrow LOINC, Narrow (SNOMED CT) to broad (LOINC), Partial overlap

originOfContent SCTID Indication of whether concept was initially in one of the terminologies (LOINC or SNOMED CT) and added to the other as part of mapping or was in both terminologies at the outset. Values • Originally in LOINC, Originally in SNOMED CT, Originally in both LOINC and SNOMED CT

Proposed release formats (2)LOINC Terms to/from SNOMED CT – Expression Refcodeset file

Field Data type Purpose

id UUID A 128 bit unsigned integer, uniquely identifying the reference set member.

effectiveTime Time Specifies the inclusive date at which this change becomes effective.

active Boolean Specifies whether the member's state was active or inactive from the nominal release.

moduleId SCTID Identifies the member version's module.

refsetId SCTID Identifies the reference set.

referencedComponentId SCTID A reference to the SNOMED CT | LOINC code system | (a filler to keep to Refset format)

mapTarget String The value of the LOINC Part Code to which the concept is mapped.

expression String SNOMED CT Expression that most closely represents meaning of the LOINC Term code.

definitionStatusId SCTID Indicates whether or not the expression contains a sufficient definition of the LOINC Term Code in the mapTarget field. Subtypes of: 900000000000444006 | Definition status

correlationId SCTID The correlation between the SNOMED CT concept and the LOINC Part Code. Subtypes of 447247004 | SNOMED CT source code to target map code correlation value|

• Exact match, Broad (SNOMED CT) to narrow LOINC, Narrow (SNOMED CT) to broad (LOINC), Partial overlap

originOfContent SCTID Indication of whether concept was initially in one of the terminologies (LOINC or SNOMED CT) and added to the other as part of mapping or was in both terminologies at the outset. Values • Originally in LOINC, Originally in SNOMED CT, Originally in both LOINC and SNOMED CT

Expression representation

▪ SNOMED CT Compositional Grammar▪ Planned approach – use author normal form expressions

▪ Proximal supertypes▪ Differential non-redundant defining relationships

▪ Actual expressions in Technology Preview▪ SNOMED CT Observable entity concepts are not yet modeled▪ There are no intermediate sufficiently defined supertypes▪ Thus for (almost) all LOINC Term codes:

▪ Proximal inferred supertype is: 363787002|Observable entity|▪ Expression refinements are full nested definitions

mapTarget expression

27182-5 363787002:70434600=(386053000:704347000=(414237002:704319004=87612001,704320005=5540006,704318007=118569000),704327008=119297000,370132008=117363000)

LOINC Term to SNOMED Expression Refset Example

LOINC Term to SNOMED Expression Refset Example

mapTarget expression

27182-5 | Calcium:ACnc:Pt:Bld:Ord |

363787002|Observable entity|: 70434600|Specified by|= (386053000|Observation procedure|: 704347000|Observes|= (414237002|Feature of entity|: 704319004|Inheres in|=87612001|Blood|, 704320005|Towards|=5540006|Calcium|, 704318007|Property type|=118569000| Arbitrary

concentration|), 704327008|Direct site|=119297000|Blood specimen|, 370132008|Scale|=117363000|Ordinal value|)

LOINC TermSNOMED attribute conceptSNOMED value concept

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Implementation Guidance on using SNOMED CT and LOINC together

▪ Phase 1: Scoping and Horizon Scan▪ Completed: 10th April

▪ Phase 2: Developing Guidance ▪ Completed draft: 11th July 2014▪ Consultation and commenting by I&E Committee▪ Current version: 14th October 2014

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Implementation Guidance SNOMED and LOINCPhase 1 deliverables: Horizon Scan

▪ Use of SNOMED CT and LOINC together▪ 12 structured use case summaries based on phone interviews ▪ Revised based in feedback from interviewees

▪ High-level summary of findings▪ National spread: 7 different countries (6 Members + 1 Non-Member)

▪ Patterns of terminology use …

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Implementation Guidance SNOMED and LOINCPhase 2 deliverables

▪ Guidance on models for combined use▪ Advice on situations in which LOINC and SNOMED CT codes

can be effectively used together. ▪ E.g. laboratory observations, test results, vital signs,

microorganisms, antibiotic sensitivities, specimen types, etc.▪ Take account of existing guidelines (e.g. HL7, CIMI)

▪ E.g. HL7, CIMI or other relevant initiatives▪ Added value from maps & expression associations

▪ Enhanced semantic processing for LOINC users ▪ Greater completeness of coverage from SNOMED CT + LOINC

Guidance on use of SNOMED CT and LOINC together (outline)

▪ Short Introduction to SNOMED CT▪ Features of SNOMED CT▪ Benefits of SNOMED CT

▪ Short Introduction to LOINC▪ Features of LOINC▪ Benefits of LOINC

▪ Cooperative work overview▪ Map Correlation and Origin Reference Set▪ Expression Association Reference Set▪ Benefits of products of the Cooperative Work

▪ Guidance on Use of SNOMED CT and LOINC Together▪ Relevant Clinical Scenarios▪ Practical guidance on uses of SNOMED CT and LOINC▪ Practical uses of Part Maps and Expression Associations

Examples of Guidelines (1)

Examples of Guidelines (2)

▪ Content▪ Alpha prototype files (including OWL file)

▪ https://csfe.aceworkspace.net/sf/frs/do/viewRelease/projects.snomed_ct_international_releases/frs.3_other_releases.loinc_snomed_alpha_prototype

▪ Technology Preview files▪ https://

csfe.aceworkspace.net/sf/frs/do/listReleases/projects.snomed_ct_international_releases/frs.technology_preview_packages

▪ Implementation▪ Horizon and scoping report (Phase 1)

▪ https://csfe.aceworkspace.net/sf/go/doc10329▪ Draft implementation guidance (Phase 2)

▪ https://csfe.aceworkspace.net/sf/go/doc10699▪ Observables redesign

▪ https://csfe.aceworkspace.net/sf/go/doc9931▪ RII – IHTSDO Agreement

▪ http://ihtsdo.org/fileadmin/user_upload/Docs_01/About_IHTSDO/Harmonization/Cooperation_Agreement_between_IHTSDO_and_RII_20130817.pdf

References

QUESTIONS & DISCUSSION