Concept addition from conception to delivery Or Why does it take long?

You can’t always get what you want  Not all medical terms can or should be represented “as is” in SNOMED The terminology should not aid and abet the use of imprecise, inaccurate, or erroneous terms The terminology should not aid and abet the use of imprecise, inaccurate, or erroneous terms Not all nuances of medical circumstances can be captured and defined within the nomenclature Not all nuances of medical circumstances can be captured and defined within the nomenclature Over-reliance on precoordination invites combinatorial explosion and limits expressivity Over-reliance on precoordination invites combinatorial explosion and limits expressivity

...but if you try sometimes, you can get what you need  The requirements of a controlled medical nomenclature restrict the addition of content  My job is to determine what content can be added, and to add it in a form that does not introduce error or ambiguity to the nomenclature

Goals  Avoid adding redundant or duplicate concepts to SNOMED  Avoid adding ambiguous, obsolete, or incorrect terms as fully specified names  Accurately define all new concepts

Preadmission questions  Do we need this concept?  What does the concept mean?  In what context will the concept be used?  Can the concept be defined in SNOMED?

Where’s Waldo? Does SNOMED already contains the concept, sometimes under another wording, or a usable equivalent?  Ex: request for Uroabdomen SNOMED already has an equivalent concept, Urine ascites, not found by searching for uroabdomen SNOMED already has an equivalent concept, Urine ascites, not found by searching for uroabdomen Adding Uroabdomen would create redundancy Adding Uroabdomen would create redundancy Request addition of Uroabdomen as synonym instead Request addition of Uroabdomen as synonym instead

Say what? In a controlled medical terminology, each concept must represent a single idea, and the concept FSN should clearly state that idea…BUT  Human and veterinary medical language contains many terms whose meaning is not evident from the wording or which convey multiple meanings Downer cow Downer cow White line disease White line disease Overeating disease Overeating disease

What this means:  Even “accepted” medical terms must often be translated, not transcribed, into SNOMED  Just because “the clinician said so” does not mean SNOMED will—or can--“say so”

Say what you mean… If commonly accepted term is ambiguous, but conveys a commonly accepted meaning: => add concept => give concept unambiguous FSN => add common name as description

Example 1: Sweeney = neurogenic atrophy of shoulder muscles

Mean what you say: If commonly used medical term conveys more than one meaning: => create separate concepts for each meaning => give each concept unambiguous FSN => assign commonly used term as synonym for each concept

Example 2 Overeating disease = Type C Enterotoxemia = Type D Enterotoxemia = Grain Overload

Saying to mean 3 If common term has complex meaning that can be best be captured by post- coordinating existing concepts => Deny concept request => Supply guidance to use of existing SNOMED concepts => Supply guidance to use of existing SNOMED concepts

Example 3 Pigeon fever  misleading name—pigeons do not get or carry it  variable presentation—+/- pectoral abscess = Abscess of pectoral region Causative agent Corynebacterium pseudotuberculosis + Causative agent Corynebacterium pseudotuberculosis OR OR = Infection due to Corynebacterium pseudotuberculosis

Say…what did you mean? Requested term obscure, outdated, inherently vague or meaning is impossible to determine from information given  seek clarification from requestor  determine if concept warranted

Just the facts, ma’am When requesting a concept, you may be asked to:  Seek clarification from a clinician  Supply background information  Explain the concept’s projected use  Discuss whether existing SNOMED concept(s) can be used instead  Accept a refusal 

Request: Myelocytoma Problem: Myelocytoma can refer to Multiple myeloma Multiple myeloma Chronic myelogenous leukemia Chronic myelogenous leukemia A discrete tumor esp. of fowl, composed of myelocytes A discrete tumor esp. of fowl, composed of myelocytes  Need to know: which meaning is intended

Request: Proliferative thrombovascular necrosis Problem: References lacking  Need to know: --is this an accepted medical term? --what is the pathophysiology? --what is the etiology, if known?

Request: Delayed weaning Problem: Context unclear Procedure or finding? Procedure or finding? If finding—necessarily abnormal? If finding—necessarily abnormal?  Need to know: context, to determine hierarchy to which concept belongs

Request: Ringwomb Problem: User requests new concept or guidance to appropriate existing concept  Need to know: exact nature of “ringwomb” to find if perfect match exists in SNOMED (yes).

Request: Chronic moist dermatitis Problem: Concept irredeemably ambiguous  Need to know: how to break clinicians of using pseudodiagnoses!

And finally….  Sliced, diced, buffed and polished concept submitted to SNOMED with suggested FSN, synonyms, and definitions  CAP modeler reviews submission—may reject, query, or accept concept  If accepted, new concept is created and assigned codes in TDE  New concept appears in next database release