snomed ct - empowering clinicians
TRANSCRIPT
SNOMED CT –EMPOWERING CLINICIANS
Dr SB Bhattacharyya
MBBS, MBA, FCGP
Member, National EHR Standardisation Committee, MoH&FW, GoI
Member, Health Informatics Sectional Committee, MHD 17, BIS
Hony. State Secretary (2015), IMA Haryana
President (2010 – 2011), IAMI
SNOMED CT
■ SNOMED CT is a semantically interoperable polyhierarchical subtype multi-lexical clinical terminology system that is able to deliver robust benefits to the health care services.
■ SNOMED CT is a reference terminology for clinical terms and consists of terms used in health and health care.
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Why SNOMED CT?
■ Natural language for end-users
– Doctors
– Dentists
– Nurses
– Paramedics
■ Since clinical documentation systems document the clinical thoughts of the observers, a concept-based system works best, not a term-based or classification-based one
■ For clinical analytics, evidence based medicine, clinical decision support, etc., the correct idea is vital, not a prefixed term
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Advantages for Clinicians
■ Users get to choose the terms that they are most comfortable with in their own language/dialect
■ Users can express their clinical thoughts very precisely using expressions
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SNOMED CT Components – Core
■ Concepts
– Concept Ids – meaningless machine-processable numbers
■ Descriptions (Terms)
– Human-processable terms
■ Relationships
– Between concepts: source to destination
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SNOMED CT Terms
■ Fully Specified Name (FSN) – identified by having the term suffixed by its top-level hierarchy enclosed in parenthesis thus -“(disorder)”, “(body structure)”, “(procedure)”, etc.
■ Preferred Term (PT)
■ Acceptable (Terms) – synonyms
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SNOMED CT Relationships
Infective pneumonia (disorder)
Lung (body structure)
Infection (disorder)Respiratory disease (disorder)
Virus (organism)
Viral pneumonia (disorder)
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SNOMED CT – Attribute Value-Range
DOMAIN(hierarchy)
ATTRIBUTERANGE
(concept of hierarchy)
<< This concept or one of its
descendants| Clinical finding | | FINDING SITE |
<< 442083009| Anatomical or acquired body
structure |
| Body structure | | LATERALITY | < 182353008 |Side|
< Descendants only. Not the concept itself
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SNOMED CT Expressions
■ Pre-coordinated
– Coordination already done : composed before-the-fact
– Through its ~ 1 million terms, most thoughts can be expressed using just this
■ Post-coordinated
– Coordination done on-the-fly by the users choosing various rules-based alternatives: composed after-the-fact
– Required intermittently, especially when the thought is a complex one and requires further refinement or qualification or combination with other terms
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Expressions
■ The actual “code” of SNOMED CT and consists of either
– ConceptId only102556003or
– ConceptId | Description (Term) | 102556003 | pain in upper limb |
■ Needs to adhere to compositional grammar rules and expression constraint syntax
■ Never to be seen by any user, clinician or otherwise, ever
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Clinicians need to work only with the terms that number more than one million…
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Requires Post-coordinated Expression
This thought includes two separate concepts :
1. Family history
2. Hypertension
These need be combined, the following postcoordinated expression needs to be created as below and used to represent this family history –
281666001 | family history of disorder | : 246090004 | associated finding | = 38341003 | hypertension |
This can also be written as –281666001 : 246090004 = 38341003
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What the Clinicians gets to choose from (list created by combining two separate SNOMED CT terms)…■ Family History of Disorder : BP - High
Blood Pressure
■ Family History of Disorder : BP+ -Hypertension
■ Family History of Disorder : HBP - High Blood Pressure
■ Family History of Disorder : High Blood Pressure
■ Family History of Disorder : High Blood Pressure Disorder
■ Family History of Disorder : HT -Hypertension
■ Family History of Disorder : HTN -Hypertension
■ Family History of Disorder : Hypertension
■ Family History of Disorder : Hypertensive Disorder
■ Family History of Disorder : Hypertensive Disorder, Systemic Arterial
■ Family History of Disorder : Hypertensive Vascular Degeneration
■ Family History of Disorder : Hypertensive Vascular Disease
■ Family History of Disorder : Systemic Arterial Hypertension
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Comments On SNOMED CT Expressions
■ NOT to be seen by any user ever
■ Akin to stuff that are handled by the machine far away from any user’s eyes, like HL7 messages that appear as but are never ever seen by any system user:MSH|^~\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4<cr>PID|||555-44-4444||EVERYWOMAN^EVE^E^^^^L|JONES|19620320|F|||153 FERNWOOD DR.^^STATESVILLE^OH^35292||(206)3345232|(206)752-121||||AC555444444||67-A4335^OH^20030520<cr>OBR|1|845439^GHH OE|1045813^GHH LAB|15545^GLUCOSE|||200202150730|||||||||555-55-5555^PRIMARY^PATRICIA P^^^^MD^^|||||||||F||||||444-44-4444^HIPPOCRATES^HOWARD H^^^^MD<cr>OBX|1|SN|1554-5^GLUCOSE^POST 12H CFST:MCNC:PT:SER/PLAS:QN||^182|mg/dl|70_105|H|||F<cr>
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Impact on Analytics
■ SNOMED CT has concept-based polyhierarchical structure based on a formal description logic and ability to support multiple languages
■ These permit broad aggregation of clinical observations, context-based interpretation of data, testing whether a particular observation is equivalent to or subsumed by some predefined set of clinical observations
■ Its multi-lingual nature permits queries to be made in any language without worrying about the language used in the record
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Impact on Analytics
■ Ability to code all parts of a clinical record permits all data to be analysed to discover clinical knowledge in them
■ Point-of-care Analytics, Population Analytics, Observational Clinical Research, Semantic Search are all possible now
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Observations On SNOMED CT
■ Not a piece of software, only a part of it
■ Akin to a gear-box of a car – on its own does nothing, when placed properly and used judiciously, it helps deliver quite a punch
■ A terminology coding system that greatly helps in automating various clinical processes including record-keeping, diagnostics, treatment planning, clinical decision support, clinical data analytics, services billing, health surveillance, etc.
■ Can code all parts of a clinical document covering terms ranging from abscess to zygote and aspects from reason for visit to outcome
■ Empower care providers to deliver best-of-possible care through the use of analytics and machine learning
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Note that ICD / LOINC ≠ SNOMED CT
ICD / LOINC
■ A meaning-based classificationsystem where the literal meaning of the term used is taken into consideration
■ Useful for reporting purposes
■ Code system for medical records department
SNOMED CT
■ A concept-based terminologysystem where the meaning of the concept behind the term is taken into consideration
■ Useful for clinical decision support and analytics, besides reporting
■ Code system for care providers
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References
■ Images are all courtesy IHTSDO, used with their kind permission
■ Matter generally based on “Introduction to SNOMED CT” by Dr SB Bhattacharyya
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Introduction to SNOMED CT by Dr SB Bhattacharyya available at
■ http://www.amazon.com/Introduction-SNOMED-CT-S-B-Bhattacharyya/dp/9812878939/ref=sr_1_1?ie=UTF8&qid=1453269681&sr=8-1&keywords=introduction+to+snomed+ct – hardcopy only
■ http://www.amazon.in/Introduction-SNOMED-CT-2016-Bhattacharyya/dp/9812878939/ref=sr_1_1?ie=UTF8&qid=1453269722&sr=8-1&keywords=introduction+to+snomed+ct – hardcopy only
■ http://www.springer.com/gp/book/9789812878939 – ebook and hardcopy
■ http://link.springer.com/book/10.1007/978-981-287-895-3 – chapter-wise online access only
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