basics of snomed ct for medical professionals

BASICS OF SNOMED CT FOR MEDICAL

PROFESSIONALSDr SB Bhattacharyya

MBBS, MBA, FCGP

Member, National EHR Standardisation Committee, MoH&FW, GoI

Member, IMA Standing Committee for IT, IMA Headquarters

Member, Health Informatics Sectional Committee, MHD 17, BIS

President (2010 – 2011), IAMI

What exactly is SNOMED CT?

SNOMED CT is a set of clinical concept codes generated by applying its Concept Model rules (Description Logics) to the concept definitions and inter-relationships (ontology) that can be used by computer systems for interpreting them

Dr SB Bhattacharyya© 2

NB: This is NOT a definition, but an explanation

Underlying principles…

■ Medical knowledge exists amongst its many terms

■ Using principles enumerated in linguistics it is possible to relate terms to concepts

■ Using principles enumerated in computer science it is possible to code concepts to help machines understand them

■ Using these principles it is possible for humans to codify medical knowledge in a manner that makes it processable by computer systems

■ This permits the systems to “infer" the medical knowledge


Why SNOMED CT

■ Medical knowledge is made concepts-based by mapping medical terms to their corresponding concepts using the principles of semasiology (terminology)

■ The principles of computer and information science are then applied to define the concepts using other concepts through ontology(specification of conceptualisation – Thomas Robert “Tom” Gruber)

■ These ontologies are then codified using Description Logics (formal concept definitions and relations – SNOMED CT concept model)


What does SNOMED CT contain?

■ The actual “codes” are the pre-coordinated or post-coordinated expressions that help define the concepts and their inter-relationships using machine-processable numbers to enable computer systems to “comprehend” them

■ Human-readable terms are provided to help identify the concepts to humans


How SNOMED CT helps medical professionals?

■ Recording clinical observations

■ Querying health records for information

■ Deriving medical knowledge from clinical documents

■ Automating repetitive jobs like posting orders thereby improving efficiency and productivity (more time for care providers to do what they are supposed to and specially trained to do – provide care)

■ Raising rules-based alerts and warnings to help reduce errors


Role of SNOMED CT in Clinical Documents

■ In any record, the author enters his thoughts that he has about an item

■ When a care provider enters a complaint or a physical exam finding or a disease, he enters his thoughts about it

■ Concepts are thoughts and the recorded clinical information represents the clinical concepts of the person making the record

■ Using SNOMED CT concepts, it is possible to code any clinical thought about any medicine-related matter

■ These codes can then be interpreted with sufficient precision by computer systems and acted upon as necessary


SEMANTICALLY MERGING DATA

How does SNOMED CT help?

Example 1


Disclaimers for the following slides used to demonstrate SNOMED CT’s capabilities…

■ All cases are FICTITIOUS and any resemblance to real life is purely coincidental and totally unintentional

■ The Hindi version of records has been specially prepared by the author for illustrative purposes only – as of mid-2017 SNOMED CT is NOT available in that language

■ The treatment plans used in the following slides have made only to illustrate the process and is not meant to be used as a recommendation of any kind


The case…

Mr Wilfred, a resident of the historic city of Leicester in UK is an old age pensioner. Frequently fed up with the gloomy dreary rainy weather that is the norm in dear old England, he escapes once a year to somewhere nice for a bit of fun and frolic in places with better climes. He fell ill and sought treatment from his regular GP in England in 2015. The next year, while basking on the sea shores of sunny Spain, he fell ill again for which he sought treatment from a local doctor over there. The year next, on his trip to view the Taj on a full moon night in exotic India, he fell ill yet again for which he sought treatment from a local doctor over there. On his current trip to Las Vegas in US of A, he fell ill yet again causing him to visit the ER department of a hospital located downtown. The doctor decided to review his previous records. What he found is provided in the next few slides…


The Records (as originally entered by the doctors)…Item Record # 1 Record # 2 Record # 3

Date & Time 18 June 2014, 11:05:00 21 October 2015,

10:30:00

21 April 2016, 12:15:00

Location Leicester, UK Marbella, Spain Agra, India

Chief

ComplaintCommon cold Tos con fiebre सिरददद की सिकायत

Past History Appendicectomy - -

Physical

Examination

O/E - pharynx

hyperaemic

Al examen: ruidos

respiratorios normales

कोई अिामान्यता नही ीं समली

- परीक्षा पररणाम

Investigations Normal Sin particularidades िाधारण

Treatment Antihistamine Agente antitusivoगैर-अफीओइड दददनािक

दवा

The Hindi version created by using Google Translation is used here only for illustrative purposes.

It does NOT exist as of mid-2017. The Spanish version, however, does…Dr SB Bhattacharyya© 11

The Records (as available to the system internally)…

Item Record # 1 Record # 2 Record # 3

Date & Time 18 June 2014, 11:05:0021 October 2015,

10:30:0021 April 2016, 12:15:00


Chief

Complaint82272006 135883003 272027003

Past History 80146002 - -

Physical

Examination268982000 162950006 282332003

Investigations 17621005 17621005 17621005

Treatment 6425004 372791003 322208004


Only the clinical aspects of the information has been coded using SNOMED CT here

The Records (as available to the ER doctor in Las Vegas, USA)…Item Record # 1 Record # 2 Record # 3

Date & Time 18 June 2014, 11:05:0021 October 2015,

10:30:0021 April 2016, 12:15:00


Chief

Complaint

Common cold Cough with fever C/O - a headache

Past History Appendectomy - -

Physical

Examination

O/E - pharynx

hyperaemic

O/E - breath sounds

normal

No abnormality

detected - examination

result

Investigations Normal Normal Normal

Treatment Antihistamine Cough suppressants Non-opioid analgesics


Discussion

■ When a user records using the set of available terms in any available preferred language / dialect (in the example, English, Spanish and Hindi), the SNOMED CT codes are stored for future use

■ When that recorded data is exchanged with an external system, the codes are made available to that system

■ Using them, the other system can map them back to the set of available terms in the preferred language / dialect

– In the example used, appendicectomy was the term entered by the doctor in the UK and appendectomy was the term read by the doctor in the US [refer back to slide #s 11 & 13 to re-check]

■ This makes it possible for any record to be viewed in a language of one’s choice provided SNOMED CT is used and the terms that identify the concepts are available in the desired language / dialect


AUTOMATIONHow does SNOMED CT help?

Example 2


Ordering Rules

■ If the disorder is appendicitisthen

– Admit the patient in hospital

– Start continuous infusion of dextrose saline

– Perform

■ a complete blood count

■ an ultrasound scan of abdomen

■ If disorder is acute appendicitisthen additionally post patient for

– Laparoscopic emergency appendectomy

■ If disorder is chronic appendicitisthen additionally post patient for

– Laparoscopic appendectomy

■ If disorder is subacute appendicitisthen additionally start

– Cefoxitin sodium 2g injection


These rules are for illustrative purposes only, not meant for actual treatment recommendations

“Code” for AppendicitisDefinition

■ Its SNOMED CT code (pre-coordinated expression) is 74400008 | appendicitis |

■ In machine-processable form this is === 18526009 + 302168000 : {116676008 = 23583003, 363698007 = 66754008}

■ In human readable form this is a disorder of appendix (disorder) and inflammation of large intestine (disorder) and has the attributes associated morphology (attribute) of inflammation (morphologic abnormality) and finding site (attribute) of appendix structure (body structure)


“Code” for Appendicitis| is a | relationships (graphical)


Screenshot from ClinClue Xplore®

“Code” for acute appendicitis

■ Its SNOMED CT code (pre-coordinated expression) is 85189001 | acute appendicitis |

■ In machine-processable form this is === 74400008 : {116676008 = 4532008, 363698007 = 66754008}

■ In human readable form this is a(n) appendicitis (disorder) and has the attributes associated morphology (attribute) of acute inflammation (morphologic abnormality) and finding site (attribute) of appendix structure (body structure)


“Code” for chronic appendicitis

■ Its SNOMED CT code (pre-coordinated expression) is 58997001 | chronic appendicitis |


■ In human readable form this is a(n) appendicitis (disorder) and has the attributes associated morphology (attribute) of chronic inflammation (morphologic abnormality) and finding site (attribute) of appendix structure (body structure)


“Code” for subacute appendicitis

■ Its SNOMED CT code (pre-coordinated expression) is 9124008 | subacute appendicitis |


■ In human readable form this is a(n) appendicitis (disorder) and has the attributes associated morphology (attribute) of acute and chronic inflammation (morphologic abnormality) and finding site (attribute) of appendix structure (body structure)


“Code” for bacterial gastroenteritis

■ Its SNOMED CT code (pre-coordinated expression) is 274080003 | bacterial gastroenteritis |

■ In machine-processable form this is === 128999004 + 312121001 : {116676008 = 23583003, 246075003 = 409822003, 363698007 = 122865005, 370135005 = 441862004}

■ In human readable form this is a(n) inflammatory disorder of digestive tract (disorder) and abacterial gastrointestinal infectious disease (disorder) and has the attributes associated morphology (attribute) of inflammation (morphologic abnormality) and causative agent (attribute) of superkingdom bacteria (organism) and finding site (attribute) of gastrointestinal tract structure (body structure) and pathological process (attribute) is infectious process (qualifier value)


Managing Treatment Plan (machine version)

■ If 74400008 is present as a record entry or in the definition of a record entry then order 32485007 and 313419007 and 26604007 and 45036003 else do nothing

■ If 85189001 then also order 174041007



■ If NOT 74400008 or NOT 85189001 or NOT 58997001 or NOT9124008 then do NOTHING


Note the coloured arrows in slide #s 17, 19, 20 & 21

Managing Treatment Plan (human version)

■ If appendicitis is present in the record entry or in the definition of a record entry then order hospital admission and continuous infusion of dextrose saline and complete blood count and ultrasonography of abdomen

■ If acute appendicitis then additionally order laparoscopic emergency appendectomy

■ If chronic appendicitis then additionally order laparoscopic appendicectomy

■ If subacute appendicitis then additionally order cefoxitin sodium 2g injection solution 50mL bag

■ If not appendicitis or not acute appendicitis or not chronic appendicitis or not subacute appendicitis then do NOTHING


Action based on entry

■ Acute appendicitis

– Is a(n) appendicitis, so order all items related to appendicitis order hospital admission and continuous infusion of dextrose salineand complete blood count and ultrasound of abdomen

– Additionally, post the patient for laparoscopic emergency appendicectomy

■ Chronic appendicitis

– Is a(n) appendicitis, so order all items related to appendicitis order hospital admission and continuous infusion of dextrose salineand complete blood count and ultrasound of abdomen

– Additionally, post the patient for laparoscopic appendicectomy


Action based on entry

■ Subacute appendicitis

– Is a appendicitis, so order all items related to appendicitis orderhospital admission and continuous infusion of dextrose saline and complete blood count and ultrasound of abdomen

– Additionally, order cefoxitin sodium 2g injection solution 50mL bag

■ Bacterial gastroenteritis

– Is not appendicitis, so do nothing


Using SNOMED CT Concept Model for automation

Based on what is entered, the system is automatically able to post the correct orders by accurately distinguishing between the concepts


Using SNOMED CT Concept Model for automation

■ In the example before, appendicitis was the broader form and acute/chronic/subacute appendicitis its granular form of the concept inflammation of large intestine

■ Although both appendicitis and bacterial gastroenteritis have the concept inflammatory disorder of digestive tract as their supertype ancestor, the former and latter are not inter-related, which makes it possible for them to be handled differently using appropriate rules


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basics of snomed ct for medical professionals

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