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SNOMED Clinical Terms User Guide

1. cccceeeeeeeeseeeeeeeeeeeeeeeeeeeeaaaes 4 27 4 10 Attributes used to define Physical object concepts ee eeeeeeeeeeeeeeeeees 4 28 4 11 Role Groups in SNOMED CT ac cesczescsctecg tk cenecsanctcsxecah ices vtesseeaeedaasncaden eerceues 4 28 O FICK ARC INOS stanss sce state at acs sl cuts lutea Meads lucas ee eBegte Pah tcetet aaa dba eetitta cele Codeen ieee neuen 5 1 5 1 Top level hierarchies in SNOMED CfT sssssssssssesserrnssesrerssrerrssrrrnnerrrenrssrrrneet 5 1 6 SNOMED CT Structure and Technology ConsiderationS cccccseeeeeeteeeeeeees 6 1 6 1 UEP OCCT OM kennen apao niaaa aa ea a AE AEAEE edie ated ened 6 1 6 2 SNOMED CT Pianola sitio aioe toe aces cntevaactvaacuk aac sexvaas eae teectberaeetinateane anaes 6 1 6 3 PLS Oi ed 9 re tant a nee eaten Cape hace eet cites Mg Prac cacateaa ds Geri ema saetiuedce 6 3 6 4 SNOMED CT SUDSOIS ioc cJeds ee e eaa ena sade decas ara arae S EESAN RRT 6 4 6 5 Gross MappihgS irriaren a a n a aa e a aa 6 5 6 6 EXTENSIONS aane a aa Ra i aaa A deed RE A A e aa 6 6 6 7 SNOMED CT applications and SErviCeS cccceecceeeeeeeeeeeeeeeteeeeeeeeeeeeeeeeeaes 6 6 Appendix A Concepts Prefaced with SyMbols cccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeneeees A 1 PBDENGKEB E ofc L A alee cate se hee weaea E E EEE B 1 Appendix C SNOMED CT Guiding Principles Development Process and Acknowledgements iso arduan a ana aee E E E A naa e C 1 SNOMED CT User Guide January 2007
2. Example Concept with granularity between that of a VTM and VMP Parenteral form epinephrine product Dose form Name Product category A Product category concept supports a group of Pharmaceutical biologic products related by their functionality mechanism of action or therapeutic use Product category concepts typically describe common drug categories used in prescribing Examples of Product category concepts e Sex hormone product product e Mineralocorticoid preparation product e Beta Blocking agent product e Tissue plasminogen activator preparation product Actual Medicinal Products AMPs SNOMED CT offers drug extensions for the US and the UK that contain Actual Medicinal Products AMPs The AMP represents the single unit dose of a medicinal product that is or has been made or marketed by a specific manufacturer trademarked brand name pharmaceutical products Its description requires product name strength dosage form flavor where applicable and manufacturer but it does not include explicit information about packaging Because AMP concepts contain brand and country specific information they are not represented within the core of SNOMED CT but instead exist within an identified domain extension Actual Medicinal Products in an extension have a direct link to their virtual equivalent in the core via the IS_A relationship Example Cetirizine hydrochloride 10mg tablet product VMP found in the core IS_A
3. SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 13 Example Incision of ureter procedure METHOD ncision action qualifier value PROCEDURE SITE DIRECT Ureteric structure body structure 4 PROCEDURE DEVICE This attribute describes devices associated with a procedure This general attribute subsumes in what is called a role hierarchy explained in Section 4 1 on Role Hierarchies the more specific attributes DIRECT DEVICE INDIRECT DEVICE USING DEVICE and USING ACCESS DEVICE which should be used instead of PROCEDURE DEVICE if possible The general attribute PROCEDURE DEVICE is mainly useful for defining high level general concepts that aggregate procedures according to the device involved Example Catheter procedure procedure DEVICE Catheter device physical object Permissible values include the following concept and its descendants e Device physical object 49062001 When the device is the focus or direct object of the procedure the attribute DIRECT DEVICE is used When the action is done on something that is located in or ona device but not directly on the device itself the attribute INDIRECT DEVICE is used When the device is used to carry out the procedure the attribute USING DEVICE is used When the device is used to access the site of the procedure the attribute USING ACCESS DEVICE is used NOTE The attributes USING and ACCESS INST
4. 5 SCALE TYPE This attribute refers to the scale of the result of an observation of a diagnostic test i e quantitative qualitative semi quantitative Permissible values include the following concepts and their descendants Quantitative qualifier value 30766002 Qualitative qualifier value 26716007 Ordinal value qualifier value 117363000 Ordinal or quantitative value qualifier value 117365007 Nominal value qualifier value 117362005 Narrative value qualifier value 117364006 Text value qualifier value 117444000 6 MEASUREMENT METHOD This attribute specifies the method by which a procedure is performed Permissible values include the following concept and its descendants Laboratory procedure categorized by method procedure 127789004 SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 21 4 5 Attributes used to define Specimen concepts NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 4 Approved Specimen attributes summary table Defining Attribute Permissible Values Concepts listed and their descendents SPECIMEN PROCEDURE Procedure 71388002 SPECIMEN SOURCE Anatomical structure body structure Acquired body structure 280115004 TOPOGRAPHY 91723000 SPECIMEN SOURCE Morphologically abnormal structure 49755003 MORPHOLOGY SPECIMEN SUBSTANCE Substance 1055900
5. Example FINDING SITE Lung structure A tool for exploring and searching the terminology content A browser can display hierarchy sections and concept details relationships between concepts descriptions and lds etc SNOMED CT uses integers up to 18 digits in length as component identifiers known as SNOMED CT Identifiers SCTIDs The check digit is the last digit of the SNOMED CT Identifier It can be used to check the validity of SCTIDs Clinical information systems can use the check digit to identify SNOMED CT codes that have been entered incorrectly typo errors etc Refers to anything in SNOMED CT identified by an SCTID The part of the SCTID called the partition identifier indicates the type of component referred to by that SCTID Examples of Components include Concepts Relationships Descriptions Subsets Cross Map Sets and Cross Map Targets A clinical idea to which a unique ConceptID has been assigned in SNOMED CT Each Concept is represented by a row in the Concepts Table When two SNOMED CT concepts or post coordinated expressions have the same meaning Concept equivalence can occur when a post coordinated expression has the same meaning as a pre coordinated Concept or when two different post coordinated expressions have the same meaning The unique identifier code for each SNOMED CT concept Refer to the SNOMED Technical Reference Guide for a full explanation of how this identifier is structured Example F
6. New range for LATERALITY attribute Changes to range for PROCEDURE SITE and FINDING SITE and SPECIMEN SOURCE TOPOGRAPHY Added section on use of attribute for Physical object hierarchy Updates to Examples SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Page v Inventory of Documentation The following documentation is currently available for SNOMED licensees from SNOMED International SNOMED CT Technical Reference Guide TRG The TRG is intended for SNOMED CT implementers such as software developers The TRG assumes an information technology background Clinical knowledge is not a prerequisite The TRG contains reference material related to the current release of SNOMED CT and includes file layouts field sizes required values and their meanings and high level data diagrams It can be used to install and use SNOMED SNOMED CT Technical Implementation Guide TIG The TIG is intended for SNOMED CT implementers such as software designers The TIG assumes information technology and software development experience Clinical knowledge is not required although some background is helpful to understand the application context and needs The TIG contains guidelines and advice about the design of applications using SNOMED CT and covers topics such as terminology services entering and storing information and migration of legacy information SNOMED CT User Guide The
7. 10 HAS INTENT This attribute specifies the intent of a procedure Permissible values include the following concept and its descendants SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 17 e Intents nature of procedure values qualifier value 363675004 Example Diagnostic bronchoscopy procedure HAS INTENT Diagnostic procedure intent qualifier value 11 RECIPIENT CATEGORY This attribute specifies the recipient of a procedure such as an individual group when this individual or group is someone other than a patient For example it can be used in blood banking procedures to differentiate between the donor and recipient Permissible values include the following concepts and their descendants e Person person 125676002 e Family social concept 35359004 e Community social concept 133928008 e Group social concept 389109008 e Donor for medical or surgical procedure person 105455006 Example Social service interview of family procedure RECIPIENT CATEGORY Family social concept 12 REVISION STATUS This attribute specifies whether a procedure is primary or a revision Permissible values include the following concepts and their descendants e Primary operation qualifier value 261424001 e Revision value qualifier value 255231005 e Part of multistage procedure qualifier value 257958009 Examples 1 Primary repair of inguinal hernia procedu
8. Zyrtec 10mg tablet product This is an AMP found in the extension All concepts in the Pharmaceutical biologic product hierarchy have a FSN tag of product regardless of their level of granularity SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 7 SNOMED CT concept i a Pharmaceutical Substance 5 ce Ott ss a IS_A Multiple Layers IS_A Multiple Layers Product C drug product class a Thrombolytic agent RS Mee produet y j Product Category functionality Tissue Plasminogen Activator Preparation product Atepiaso product D HAS ACTIVE INGREDIENT lt Alteplase substance gt K VMP Alteplase 10 mg powder and solvent for injection solution vial AMP AMP Ktivase 10 mg powder E solven Actilyse 10 mg owde dra and solven for injection solution vial for injection solution vial Extensions US Drug Extension sion UK Drug Extension Figure 5 1 Pharmaceutical Biologic Product hierarchy structure SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 8 Specimen The Specimen hierarchy contains concepts representing entities that are obtained usually from a patient for examination or analysis Specimen concepts can be defined by attributes which specify the normal or abnormal body structure from which they are
9. a check digit and a partition identifier It doesn t always include a namespace identifier The body responsible for policy and overall management of SNOMED Clinical Terms The body with primary responsibility for the clinical content of SNOMED Clinical Terms The Standards Board is responsible to the SNOMED International Authority The last version of SNOMED prior to the collaboration between CAP and the NHS to develop SNOMED Clinical Terms SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Glossary Page B 6 Subset Synonym Top Level Concept A group of Components e g Concepts Descriptions or Relationships that share a specified common characteristic or common type of characteristic Examples UK English Subset Non Human Subset A term that is an acceptable alternative to the Preferred Term asa way of expressing a Concept Synonyms allow representations of the various ways a concept may be described Synonyms and Preferred Terms unlike FSNs are not necessarily unique More than one concept might share the same Preferred term or Synonym A Concept that is an immediate child of the root concept SNOMED CT Concept which is at the top of the entire SNOMED CT hierarchy of concepts SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Guiding Principles and Acknowledgements Page C 1 Appendix C SNOMED CT G
10. Each row in this table represents one member of a Subset The member may be a Concept or a Description One or more Subsets may be packaged together in this table 6 5 Cross Mappings Introduction Cross Mappings enable SNOMED CT to effectively reference other terminologies and classifications Each cross map matches SNOMED concepts with another coding scheme that is called the target scheme The Cross Mapping mechanism enables the distribution of Cross Maps from SNOMED Clinical Terms in a common structure The cross mapping structure enables e Automatic mapping from one SNOMED CT Concept to a single appropriate matching code in the Target Scheme e Automatic mapping from one SNOMED CT Concept to a single collection of codes in a Target Scheme that together represent the same Concept e Manual choice from a set of options for mapping a SNOMED CT Concept to a Target Scheme with several possible ways of representing the same or similar Concepts For Future Use The cross mapping structure does not enable e Mapping from post coordinated collections of SNOMED CT Concepts to a single Target Code or a specific collection of Target Codes e g mapping a combination of a disorder qualified by severity or a procedure qualified by urgency e Mapping from multiple fields in a patient record to a specific Target Code that represents a combination of characteristics e g mapping a combination of a disorder procedure and the age
11. SCALE TYPE Quantitative 30766002 Nominal value 117362005 Qualitative 26716007 Narrative value 117364006 Ordinal value 117363000 Text value 117444000 Ordinal or quantitative value 117365007 MEASUREMENT METHOD Laboratory procedure categorized by method 127789004 1 HAS SPECIMEN This attribute specifies the type of specimen on which a measurement or observation is performed Permissible values include the following concepts and their descendants e Specimen specimen 123038009 2 COMPONENT This attribute refers to what is being observed or measured by a procedure Permissible values include the following concepts and their descendants e Substance substance 105590001 e Observable entity observable entity 363787002 e Cell structure cell structure 4421005 e Organism organism 410607006 Example Protein measurement procedure COMPONENT Protein substance 3 TIME ASPECT This attribute specifies temporal relationships for a measurement procedure Permissible values include the following concept and its descendants e Time frame qualifier value 7389001 4 PROPERTY This attribute specifies the kind of property being measured e g concentration Permissible values include the following concept and its descendants SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 20 Property of measurement qualifier value 118598001
12. When a single concept identifier is used to represent a clinical idea SNOMED CT also allows the use of post coordinated expressions see post coordination to represent a meaning using a combination of two or more concept identifiers Including commonly used concepts in a pre coordinated form makes the terminology easier to use A concept is primitive when its modeling roles and parents does not fully express its meaning A concept definition is the list of its relationships to other concepts Primitive concepts do not have the unique relationships needed to distinguish them from their parent or sibling concepts Some SNOMED CT concepts can have Qualifying attributes which are optional non defining relationships that may be applied by a user or implementer in post coordination The qualifier value mechanism in SNOMED CT constrains the possible values an implementer can select in assigning a qualifying characteristic to a concept The second version of the clinical coding scheme developed by Dr James Read Read Codes Version 2 is UK Crown Copyright A sphere of authority expertise or preference that influences the range of Components required or the frequency with which they are used A Realm may be a nation an organization a professional discipline a specialty or an individual user An association between two Concepts The nature of the association is indicated by a Relationship Type Each Relationship is represented by a row in
13. a given condition it was easily confused with the attribute COURSE used to represent the clinical course of a condition Because there was not consistent agreement between observers making this distinction the two attributes were retired The new attribute CLINICAL COURSE is used to capture information previously represented with COURSE and ONSET 6 EPISODICITY There was a change in the use meaning of this attribute in the July 2006 release EPISODICITY originated in the National Health Service Clinical Terms Version 3 where it was used not to specify the first episode of a disease for a patient but rather the first time a patient presented to their general practitioner GP for a particular disorder A first episode of asthma was not intended to represent the first time a patient had asthma but rather the first time a patient presented to their GP with asthma EPISODICITY has been removed from existing concepts and is no longer used in pre coordinated definitions It can still be used in post coordination as a qualifier Current permissible values include the following concept and its descendants e Episodicities qualifier value 288526004 7 INTERPRETS This attribute refers to the entity being evaluated or interpreted when an evaluation interpretation or judgment is intrinsic to the meaning of a concept This attribute is usually grouped with the HAS INTERPRETATION attribute Permissible values include the following concepts and
14. administrative groupings or classifications such as DRGs or ICD10 e Asystem designed to support design and or implementation of messages that convey specified information using a specified set of SNOMED CT concept identifiers The SNOMED CT Technical Implementation Guide TIG provides information and guidance for software professionals responsible for designing developing and implementing SNOMED CT enabled software applications The TIG describes the technical requirements and design issues for integrating SNOMED CT into new and existing applications SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Concepts Prefaced with Symbols Page A 1 Appendix A Concepts Prefaced with Symbols There are some concepts in SNOMED CT that are prefaced with a symbol in square brackets These concepts were inherited from CTV3 and were used to facilitate mapping to ICD 10 Most have been assigned a limited concept status and are not recommended for use in clinical records Explanations of these concepts are as follows X Concepts starting with X were initially used in the Read codes in the 1995 release in order to identify ICD 10 concepts that were not present in ICD 9 D Concepts starting with D are also from CTV3 and identify concepts contained in ICD 9 chapter XVI Symptoms signs and ill defined conditions and ICD 10 chapter XVIII Symptoms signs and abnormal clinical and laboratory f
15. concepts a source concept ConceptlD1 a target concept ConceptlD2 and a relationship type Each row in the Relationships Table represents a relationship triplet ConceptID1 RelationshipType ConceptlD2 identified by a RelationshipID Refer to the SNOMED Technical Reference Guide for a full explanation of how this identifier is structured A data table consisting of rows each of which represents a Relationship A version of SNOMED CT released on a particular date Except for the initial release of SNOMED CT that was called SNOMED CT First Release subsequent releases use the release date Examples SNOMED CT July 2003 Release SNOMED CT Spanish Edition April 2003 Another name for Attribute The single Concept SNOMED CT Concept that is at the top of the entire SNOMED CT hierarchy of concepts A software application designed to support the use of SNOMED CT An acronym for the Systematized Nomenclature of Medicine developed by the College of American Pathologists The clinical terminology maintained and distributed by the SNOMED International Authority under the editorial guidance of the SNOMED International Standards Board The First Release of SNOMED Clinical Terms was the result of the merger of the CTV3 and SNOMED RT A unique identifier applied to each SNOMED CT component Concept Description Relationship Subset etc The SCTID can include an item identifier namespace identifier
16. descendants e Anatomical structure body structure 91723000 e Acquired body structure body structure 280115004 Examples 1 Kidney disease disorder FINDING SITE Kidney structure body structure 2 Appendicitis disorder FINDING SITE Appendix structure body structure 2 ASSOCIATED MORPHOLOGY This attribute specifies the morphologic changes seen at the tissue or cellular level that are characteristic features of a disease Permissible values include the following concept and its descendants e Morphologically abnormal structure morphologic abnormality 49755003 Examples 1 Bone marrow hyperplasia disorder ASSOCIATED MORPHOLOGY Hyperplasia morphologic abnormality 2 Pancreatitis disorder ASSOCIATED MORPHOLOGY Inflammation morphologic abnormality 3 ASSOCIATED WITH This attribute asserts an interaction between two concepts beyond simple co occurrence in the patient ASSOCIATED WITH represents a clinically relevant association between concepts without either asserting or excluding a causal or sequential relationship between the two Permissible values include the following concepts and their descendants e Clinical finding finding 404684003 e Procedure procedure 71388002 e Pharmaceutical biologic product product 373873005 e Substance substance 105590001 e Organism organism 410607006 e Physical object physical object 260787004 e Physical force physical force 78621006 e Event event 2
17. structure USING SUBSTANCE Contrast media substance 15 USING ENERGY This is a new attribute introduced in the January 2007 release This attribute describes the energy used to execute an action USING ENERGY has been introduced because the new attribute USING DEVICE is now used only to represent the instrument or equipment used to execute the action Unlike the attribute USING which it replaces USING DEVICE does not take values from the physical force hierarchy Permissible values include the following concepts and its descendants e Physical force physical force 78621006 Example Gamma ray therapy procedure USING ENERGY Gamma radiation physical force SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 19 4 4 Attributes used to define Measurement Procedure concepts The following six attributes are used by the LOINC integration table but have not been fully modeled in SNOMED NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 3 Approved Measurement Procedure attributes summary table Defining Attribute Permissible Values Concepts listed and their descendents HAS SPECIMEN Specimen 123038009 COMPONENT Substance 105590001 Cell structure 4421005 Observable entity 363787002 Organism 410607006 TIME ASPECT Time frame 7389001 PROPERTY Property of measurement 118598001
18. technology background may be helpful it is not required to benefit from this User Guide Technical professionals who support the implementation of SNOMED CT or who develop systems that will use SNOMED CT may find this guide helpful in providing a high level overview of the terminology structure and content However for detailed technical guidance technical professionals should consult the SNOMED CT Technical Reference Guide TRG and SNOMED CT Technical Implementation Guide TIG as well as other applicable technical documentation described in the Inventory of Documentation 1 3 Notation used in this document The following notation is used in this User Guide to represent key types of SNOMED CT information e SNOMED CT Concept names are generally represented using the Fully Specified Name in italics Example Peribronchial pneumonia disorder e SNOMED CT Attributes are represented in all capital letters Example FINDING SITE SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Introduction Page 1 2 1 4 Additional information Further information about SNOMED CT is available on the Internet at http www snomed org Please send your feedback to email address snomed cap org or contact SNOMED International College of American Pathologists 325 Waukegan Road Northfield Illinois 60093 2750 Tel 1 800 323 4040 1 847 832 7700 SNOMED CT User Guide January 2007 Relea
19. the Relationships Table The nature of a Relationship between two Concepts The RelationshipType field indicates the ConceptID for the concept in SNOMED that forms the relationship between two other concepts ConceptID1 and ConceptID2 SNOMED CT has four types of relationships e Defining characteristics are IS_A relationships and defining attributes Example PROCEDURESITE DIRECT Liver is a defining characteristic of Biopsy of liver procedure e Qualifying characteristics are non defining qualifying attributes e Historical relationships relate inactive concepts to active concepts For example a concept may be inactivated because it is a duplicate In this example a relationship is created when one concept is inactivated and stated to be the same as another concept e Additional relationships are other non defining characteristics like PART OF which is retained for backward compatibility with SNOMED RT SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Glossary Page B 5 Relationship ID Relationships Table Release Version Role Root Concept SCT Enabled Application SNOMED SNOMED Clinical Terms SNOMED CT SNOMED Clinical Terms Identifier SCTID SNOMED International Authority SNOMED International Standards Board SISB SNOMED Reference Terminology SNOMED RT A SCTID that uniquely identifies a Relationship between three
20. their descendants e Observable entity observable entity 363787002 e Laboratory procedure procedure 108252007 e Evaluation procedure procedure 386053000 Example Decreased muscle tone finding INTERPRETS Muscle tone observable entity HAS INTERPRETATION Decreased qualifier value SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 8 8 HAS INTERPRETATION This attribute is always grouped with the attribute INTERPRETS and designates the judgment aspect being evaluated or interpreted for a concept e g presence absence degree normality abnormality etc Permissible values include the following concepts and their descendants e Findings values qualifier value 260245000 e Result comments qualifier value 281296001 Example Decreased muscle tone finding INTERPRETS Muscle tone observable entity HAS INTERPRETATION Decreased qualifier value 9 PATHOLOGICAL PROCESS This attribute provides information about the underlying pathological process for a disorder that is not structural and not represented by the ASSOCIATED MORPHOLOGY attribute Permissible values include the following concept e Autoimmune qualifier value 263680009 Example Autoimmune parathyroiditis disorder PATHOLOGICAL PROCESS Autoimmune qualifier value 10 HAS DEFINITIONAL MANIFESTATION This attribute links disorders to clinical findings that are always present by defini
21. 01 SPECIMAN SOURCE IDENTITY Person 125676002 Donor 261008006 Family 35359004 Device 49062001 Community 133928008 Environments 276339004 1 SPECIMEN PROCEDURE This attribute identifies the procedure by which a specimen is obtained Permissible values include the following concept and its descendants e Procedure procedure 71388002 Examples 1 Urine specimen obtained by clean catch procedure specimen SPECIMEN PROCEDURE Urine specimen collection clean catch procedure 2 Specimen from stomach obtained by total gastrectomy specimen SPECIMEN PROCEDURE Total gastrectomy procedure 2 SPECIMEN SOURCE TOPOGRAPHY This attribute specifies the anatomic site from which a specimen is obtained Permissible values include the following concepts and their descendants e Anatomical structure body structure 91723000 e Acquired body structure body structure 280115004 Examples 1 Cervix cytologic material specimen SPECIMEN SOURCE TOPOGRAPHY Cervix uteri structure body structure 2 Omentum biopsy sample specimen SPECIMEN SOURCE TOPOGRAPHY Omentum structure body structure SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 22 3 SPECIMEN SOURCE MORPHOLOGY This attribute names the morphologic abnormality from which a specimen is obtained Permissible values include the following concept and its descendants e Morphologically abnormal stru
22. 72379006 e SNOMED CT Concept 138875005 For this concept only the concept and not all of its descendents is allowed as a value SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 5 ASSOCIATED WITH subsumes the following more specific attributes in what is called a role hierarchy explained in the section on Role Hierarchies e AFTER e DUETO e CAUSATIVE AGENT AFTER This attribute is used to model concepts in which a clinical finding occurs after another clinical finding or procedure Neither asserting nor excluding a causal relationship it instead emphasizes a sequence of events Permissible values include the following concepts and their descendants e Clinical finding finding 404684003 e Procedure procedure 71388002 Example Post viral disorder disorder AFTER Viral disease disorder DUE TO This attribute is used to relate a Clinical finding directly to its cause If a clinical finding merely predisposes to or worsens another disorder rather than causing it directly then the more general attribute ASSOCIATED WITH is used instead Permissible values include the following concepts and their descendants e Clinical finding finding 404684003 e Event event 272379006 Example Acute pancreatitis due to infection disorder IS_A Acute pancreatitis disorder DUE TO Infectious disease disorder CAUSATIVE AGENT This attribute identifies the dir
23. CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 16 Examples 1 Intranasal ethmoidectomy procedure APPROACH Intranasal approach qualifier value 2 Abdominal hysterectomy procedure APPROACH Abdominal approach qualifier value 7 DIRECT SUBSTANCE This attribute describes the Substance or Pharmaceutical Biologic product on which the procedure s method directly acts Permissible values include the following concepts and their descendants e Substance substance 105590001 e Pharmaceutical biologic product product 373873005 When there is a choice the use of Substance is preferred over Product Example Injection of prostaglandin procedure METHOD Injection action qualifier value DIRECT SUBSTANCE Prostaglandin substance 8 PRIORITY This attribute refers to the priority assigned to a procedure Permissible values include the following concept and its descendants e Priorities qualifier value 272125009 Example Emergency cesarean section procedure PRIORITY Emergency qualifier value 9 HAS FOCUS This attribute specifies the Clinical finding or Procedure which is the focus of a procedure Permissible values include the following concepts and their descendants e Clinical finding finding 404684003 e Procedure procedure 71388002 Example Cardiac rehabilitation assessment regime therapy HAS FOCUS Cardiac rehabilitation regime therapy
24. CTID If no namespace is identified in a SCTID itis assumed that the component is part of the core of SNOMED CT In these cases SCTIDs can be used in an abbreviated form without the seven digit namespace identifier The partition identifier is a two digit number just to the left of the check digit in the SCTID The first of these two digits indicates whether the SCTID refers to a SNOMED CT Component in the core indicated by a 0 as the first digit in the partition identifier or a Component in an extension indicated by a 1 as the first digit in the partition identifier The second of the two digits in the partition identifier indicates which of the partitions of SNOMED CT the SCTID is identifying The partitions of SNOMED CT are indicated by the partition ID as follows 00 A Concept 01 A Description 02 A Relationship 03 A Subset 04 A Cross Map Set 05 A Cross Map Target Post coordination describes representation of a clinical meaning using a combination of two or more codes SNOMED CT allows many concepts to be represented in a post coordinated form One form of post coordination involves creating a single expression consisting of several concepts related by attributes SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Glossary Page B 4 Pre coordination Primitive Concept Qualifying attribute Read Codes Version 2 Realm Relationship Relationship Type
25. E in the concept shown below is taken from the Body structure hierarchy not the Qualifier value hierarchy e Pneumonia disorder FINDING SITE Lung structure body structure Examples of Qualifier value concepts e Unilateral qualifier value e Left qualifier value e Mild qualifier value Special concept One sub hierarchy of Special concept is Inactive concept which is the supertype for all concepts that have been retired and point to an active concept in the terminology Record Artifact A Record artifact is an entity that is created by a person or persons for the purpose of providing other people with information about events or states of affairs In general a record is virtual that is it is independent of its particular physical instantiation s and consists of its information elements usually words phrases and sentences but also numbers graphs and other information elements Record artifacts need not be complete reports or complete records They can be parts of larger record artifacts For example a complete health record is a record artifact that also may contain other record artifacts in the form of individual documents or reports which in turn may contain more finely granular record artifacts such as sections and even section headers SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Page 6 1 6 SNOMED CT Structure and Techn
26. ED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 28 4 10 Attributes used to define Physical object concepts NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 6 Attributes for Physical object concepts summary table Defining Attribute Permissible Values Concept listed and its descendents HAS ACTIVE INGREDIENT Substance 105590001 A limited number of concepts drug eluting stents reside in both the Pharmaceutical biologic product hierarchy and the Physical object hierarchy Because the HAS ACTIVE INGREDIENT attribute was applied to these concepts in the Pharmaceutical biologic product hierarchy it is applied to these concepts in the Physical object hierarchy Definitive editorial policies for the use of attributes in the Physical object hierarchy have yet to be established 4 11 Role Groups in SNOMED CT Multiple attributes and their values can be grouped together into Role groups to add clarity to concept definitions A Role group combines an attribute value pair with one or more other attribute value pairs Role groups originated to add clarity to Clinical finding concepts where there are multiple ASSOCIATED MORPHOLOGIES and multiple FINDING SITES and to Procedures in which there are multiple METHODS and multiple PROCEDURE SITES In the case of Procedures role groups associate the co
27. NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 5 Attributes for Body structure concepts summary table Defining Attribute Permissible Values LATERALITY Side 182353008 Left 7771000 Right 24028007 Right and left 51440002 Unilateral 66459002 LATERALITY This attribute provides information on whether a body structure is left right bilateral or unilateral It is applied only to bilaterally symmetrical body structures which exist on opposite sides of the body Permissible values include the following concepts e Side qualifier value 182353008 e Left qualifier value 7771000 e Right qualifier value 24028007 e Right and left qualifier value 51440002 e Unilateral qualifier value 66459002 Example Left kidney structure body structure LATERALITY Left qualifier value 4 7 Attributes used to define Pharmaceutical Biologic Product concepts NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 6 Approved Pharmaceutical Biologic Product attributes summary table Defining Attribute Permissible Values Concepts listed and their descendents HAS ACTIVE INGREDIENT Substance 105590001 HAS DOSE FORM Type of drug preparation 105904009 1 HAS ACTIVE INGREDIENT This attribute indicates the active ingredient of a drug product linking the Pharmaceutical Biologic product hierarchy to the Substanc
28. OMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Glossary Page B 3 Language subset Mapping Mechanism Modeler Modeling Namespace or Namespace identifier Partition identifier Post coordination SNOMED CT can be translated into any language or dialect These translations use existing SNOMED CT concepts along with new language specific descriptions A language subset is a set of references to the descriptions that are members of a language edition of SNOMED CT Additionally this subset specifies the type of description FSN Preferred Term or synonym SNOMED CT provides a mechanism for mapping concepts to other terminologies and classifications This mapping mechanism consists of three tables Cross Map Sets Table Cross Maps Table and Cross Map Targets Table The SNOMED CT content developers who model the terminology Also referred to as Clinical Editors or Authors The process of editing concepts to reflect their unique definition and meaning When an organization creates an extension to SNOMED CT the new components in the extension need to be identified as part of that particular organization s extension SNOMED CT does this by allocating an identifier to the organization the Namespace identifier The organization would include its namespace identifiers as part of the identifiers originated in its namespace The Namespace identifier is part of the S
29. Page 3 5 supertypes modeled with IS_A relationships and a set of defining attributes that capture the semantics of a concept and help to differentiate it from the other concept definitions including its supertypes In the example below Lumbar discitis disorder a concept in the Clinical finding hierarchy is related to concepts in the Body structure hierarchy through two attributes FINDING SITE and ASSOCIATED MORPHOLOGY Example Lumbar discitis disorder FINDING SITE Structure of lumbar intervertebral disc body structure ASSOCIATED MORPHOLOGY Inflammation morphologic abnormality The two attributes FINDING SITE and ASSOCIATED MORPHOLOGY and their assigned values provide definition for the concept Lumbar discitis disorder Example Part of the logical definition a list of a concepts relationships to other concepts of the concept Pneumonia disorder in SNOMED CT is Pneumonia disorder FINDING SITE Lung structure body structure In this example the concept Pneumonia disorder is characterized with the attribute FINDING SITE Since pneumonia is a disorder of the lung FINDING SITE has the value Lung structure body structure SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 1 4 Attributes Used in SNOMED CT 4 1 Introduction SNOMED CT currently uses over 50 defining attributes to model concept definitions Each SNOMED CT attribute can
30. Preferred Term Each concept has one Preferred Term meant to capture the common word or phrase used by clinicians to name that concept For example the concept 54987000 Repair of common bile duct procedure has the Preferred term Choledochoplasty to represent a common name clinicians use to describe the procedure Unlike FSNs Preferred Terms are not necessarily unique Occasionally the Preferred Term for one concept may also be a Synonym or the Preferred Term for a different concept SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Basic Components Page 3 3 Example Cold sensation quality qualifier value has a preferred term of Cold Common cold disorder also has a synonym of Cold In both cases cold represents a common clinical phrase used to capture the meaning of the FSN Synonym Synonyms represent any additional terms that represent the same concept as the FSN Synonyms like Preferred Terms are not required to be unique across concepts Example Some of the Synonyms associated with ConceptlD 22298006 which has the Fully Specified Name Myocardial infarction disorder are e Synonym Cardiac infarction Description ID 37442013 e Synonym Heart attack Description ID 37443015 e Synonym Infarction of heart Description D 37441018 3 3 Relationships Relationships link concepts in SNOMED CT There are four types of relationships that
31. RUMENT have been retired USING DEVICE and USING ACCESS DEVICE have been added DIRECT DEVICE This attribute represents the device on which the method directly acts Permissible values include the following concept and its descendants e Device physical object 49062001 Example Removal of arterial stent procedure METHOD Removal action qualifier value DIRECT DEVICE Arterial stent physical object SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 14 INDIRECT DEVICE This attribute models action done on something that is located in or on a device but is not done directly on the device itself Permissible values include the following concept and its descendants e Device physical object 49062001 For the example below the vegetation is being excised The mitral valve prosthesis is where the excised vegetation is located but the mitral valve prosthesis itself is not excised Thus mitral valve prosthesis is the INDIRECT DEVICE Example Excision of vegetations from implanted mitral valve procedure METHOD Excision action qualifier value DIRECT MORPHOLOGY Vegetation morphologic abnormality INDIRECT DEVICE Mitral valve prosthesis device physical object PROCEDURE SITE INDIRECT Mitral valve structure body structure NOTE The attribute INDIRECT DEVICE is infrequently used USING DEVICE This attribute refers to the instrument or equipment util
32. Release 2002 2007 College of American Pathologists Page iii Document History Date Version Notes January 2006 January 2006 User Guide revision e Modified guide organization and structure Updated descriptions and examples for SNOMED CT attributes and hierarchies Added overview of SNOMED CT structure and technology considerations e Revised glossary July 2006 July 2006 User Guide revision highlights e Added section on the use of attributes for Event hierarchy Updated Attributes used to define Clinical findings in section 4 2 Modifications were made to use of SEVERITY EPISODICITY and PATHOLOGICAL PROCESS Renamed Context dependent category context dependent category hierarchy to Situation with explicit context situation Updated Attributes used to define Procedure concepts in section 4 3 Added ROUTE OF ADMINISTRATION as an attribute January 2007 January 2007 User Guide revision highlights e Update to Attributes used to define Clinical findings in section 4 2 COURSE and ONSET were retired CLINICAL COURSE was introduced e Update to Attributes used to define Procedure concepts in section 4 3 Retired USING and ACCESS INSTRUMENT Replaced with USING DEVICE and USING ACCESS DEVICE Changes to ACCESS attribute New attributes USING SUBSTANCE and USING ENERGY SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Page iv
33. SNOMED Clinical Terms User Guide January 2007 Release 2002 2007 College of American Pathologists Page i SNOMED SNOMED International SNOMED RT and SNOMED CT are registered trademarks of the College of American Pathologists All rights reserved 2002 2007 College of American Pathologists SNOMED CT has been created by combining SNOMED RT and Clinical Terms Version 3 formerly known as the Read codes which was created on behalf of the U K Department of Health and is a Crown copyright SNOMED RT is a copyrighted work of the College of American Pathologists 2000 College of American Pathologists Clinical Terms Version 3 was created on behalf of the United Kingdom s Department of Health and is a Crown copyright SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Page ii Table of Contents DOCUMENT HIStory ncnia een oan ar Ne oe eel iii Inventory Of Documentation ssch cacsnetsess ts heneencagenevnede thsaat Lacnielenttuasetaeetaenietaeln tens abe Vv 1 ITMTKOGUICTIONN 25 ccshccni5 E Salsas coadeusdensaccvs bu cvy E ces padunaapunectediessdieedsdccnwncondaceade 1 1 1 1 PUNO SO cocci E E Boek che ahs sen tact aanlaay adeno Semdenk Soha sees heteegestee EST 1 1 1 2 Who should read this guide ac cesticcccescnciee wetrtens etree ddtetimacscagedele 1 1 1 3 Notation used in this document iviciesc csi cece eae ea ad eee eee 1 1 1 4 Additional informat
34. User Guide is intended for clinical personnel business directors software product managers and project leaders information technology experience though not necessary can be helpful The User Guide is intended to explain SNOMED CT s capabilities and uses from a content perspective It explains the content and the principles used to model the terminology SNOMED CT Subset Kit The Subset Kit is a collection of documents for individuals and organizations intending to create a Subset of the SNOMED CT terminology The Subset Kit consists of the following components e SNOMED CT Subset Planning Guide The Planning Guide is intended to help users manage the process of creating a subset of SNOMED CT This guide is intended for those responsible for creating the specifications for the subset and the maintenance strategy e SNOMED CT Subset Development Guide The Development Guide is intended to help users create and implement a subset of SNOMED CT It provides guidance on the specific tasks required e SNOMED CT Subset Editor User Guide The User Guide is intended for individuals working hands on with the Subset Editor software described below It explains how to use the software as well as its capabilities and options SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Page vi SNOMED CT Subset Editor The Subset Editor is a tool that facilitates the creation of subsets both through t
35. and sex of the patient to a single group code This structure is based on the practical experience of the Cross Mapping tables of Clinical Terms Version 3 CTV3 one of SNOMED CT s sourcing terminologies Cross Mapping tables The SNOMED CT structure to support Cross Mapping includes three tables e Cross Map Sets Table Each row in this table represents a Target Scheme for which Cross Maps are available e Cross Maps Table Each row in this table represents one option for mapping a SNOMED CT Concept to a target code or set of codes in the Target Scheme e Cross Map Targets Table Each row in this table represents a code or set of codes in the Target Scheme which provides a mapping for one or more SNOMED CT Concepts SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Page 6 6 6 6 Extensions Introduction SNOMED CT is a deep and detailed clinical terminology with a broad scope However some groups of users will need additional Concepts Descriptions or Subsets to support national local or organizational needs The Extension mechanism is a structure that enables authorized organizations to add Concepts Descriptions Relationships and Subsets to complement the core content of SNOMED CT One example of the Extension mechanism is for extensibility of SNOMED CT for the specialized terminology needs of an organization Goals of Extensions a
36. arious attributes assigned to concepts in this hierarchy accomplish this Examples of Situation with explicit context concepts e Family history Myocardial infarction situation e No family history of stroke situation e Nasal discharge present situation e Suspected epilepsy situation Observable entity Concepts in this hierarchy can be thought of as representing a question or procedure which can produce an answer or a result For instance Left ventricular end diastolic pressure observable entity could be interpreted as the question What is the left ventricular end diastolic pressure or What is the measured left ventricular end diastolic pressure Observables are elements that could be used to code elements on a checklist or any element where a value can be assigned Color of nail observable entity is an observable Gray nails finding is a finding having a parent of Nail discoloration finding One use for Observable entities in a clinical record is to code headers on a template For example Gender observable entity could be used to code a section of a template titled Gender where the user would choose male or female Female gender would then constitute a finding Body structure Body structure concepts include normal as well as abnormal anatomical structures Normal anatomical structures can be used to specify the body site involved by a disease or procedure Examples of Body structure con
37. arthritis disorder is a supertype of Streptococcal arthritis disorder 5 1 Top level hierarchies in SNOMED CT e Clinical finding e Physical force e Procedure e Event e Observable entity e Environments geographical locations e Body structure e Social context e Organism e Situation with explicit context e Substance e Staging and scales e Pharmaceutical biologic product e Linkage concept e Specimen e Qualifier value e Special concept e Record artifact e Physical object Clinical finding Concepts in this hierarchy represent the result of a clinical observation assessment or judgment and include both normal and abnormal clinical states Examples of Clinical finding concepts e Clear sputum finding e Normal breath sounds finding e Poor posture finding The Clinical finding hierarchy contains the sub hierarchy of Disease Concepts that are descendants of Disease or disorders are always and necessarily abnormal clinical states Multi axial subtype hierarchies allow diseases to be subtypes of other disorders as well as subtypes of findings SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 2 Examples of Disease concepts e Tuberculosis disorder e Non Hodgkin s lymphoma disorder Procedure Procedure concepts represent activities performed in the provision of health care This hierarchy represents a broad variety of activities including
38. at represents the value assigned in an attribute relationship The most common RelationshipType used in SNOMED is the IS_A relationship a k a subsumption relationship hierarchical relationship supertype subtype relationship or parent child relationship When an IS_A relationship is listed in the Relationships Table it indicates that Concept1 is a subtype of Concept2 6 See the Technical Reference Guide for more information about SNOMED CT tables Core tables Cross mapping mechanism Relationship CrossmapSet History mechanism 17 ComponenthHistory pT a7 Lo Oz a NI Description CrossmapTarget Subset mechanism O One SubsetMember OoOo Complements Subset Kit and Editor Terminology browser Subsets Canonical table Indexes Subset Duplicate terms Word equivalents Navigation hierarchies Figure 6 2 SNOMED CT data structure summary 6 3 History Introduction The content of SNOMED CT evolves with each release The types of changes made include new Concepts new Descriptions new Relationships between Concepts new Cross Maps and new Subsets as well as updates and retirement of any of these Components Drivers of these changes include changes in understanding of health and SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Pa
39. ble the Descriptions table and the Relationships table are commonly referred to as the core tables The association of a set of Descriptions and a set of Relationships to each Concept is implemented using the ConceptID which is the primary or foreign key in the three tables Relationshipld Conceptld Descriptionld Conceptld1 ConceptStatus J DescriptionStatus RelationshipType FullySpecifiedName Conceptld Conceptld2 CTV3ID Term CharacteristicType SNOMEDID DescriptionType Refinability i IsPrimitive 7 InitialCapitalStatus RelationshipGroup LanguageCode Figure 6 1 SNOMED CT table structure SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Page 6 2 The Concepts Table The Concepts Table contains all the concepts in SNOMED CT Each concept is represented by one row of the table Each row of the Concepts Table contains the following fields SNOMED CT concepts are identified by their ConceptlDs and all information about a SNOMED CT concept is ultimately linked to the ConceptID ConceptID is the primary key of the Concepts Table e The original SNOMED RT identifier and original CTV3 identifier for each concept that originated in those terminologies Any newly created SNOMED CT concept is assigned a SNOMED RT identifier and a CTV3 identifier This allows users of SNOMED CT to work with legacy data code
40. but not limited to invasive procedures Excision of intracranial artery procedure administration of medicines Pertussis vaccination procedure imaging procedures Ultrasonography of breast procedure education procedures Low salt diet education procedure and administrative procedures Medical records transfer procedure Examples of Procedure concepts e Removal of ureteral catheter procedure e Intravenous steroid injection procedure Irrigation of oral wound procedure Appendectomy procedure Situation with explicit context This hierarchy was called Context dependent Category until the July 2006 release The hierarchy was renamed to better describe the meaning of the concepts in this hierarchy Concepts in the Procedure and Clinical findings hierarchies given the appropriate record structure can be used in a clinical record to represent e Conditions and procedures that have not occurred e g Endoscopy arranged situation e Conditions and procedures that refer to someone other than the patient e g Family history Diabetes mellitus situation Discussed with next of kin situation e Conditions and procedures that have occurred at some time other than in the present e g History of aortic aneurysm situation History of splenectomy situation In each of these examples clinical context is specified The second example in which someone other than the patient is the focus of the concept could b
41. can be assigned to concepts in SNOMED CT e Defining e Qualifying e Historical e Additional The relationships addressed in this section are known as defining relationships which are used to model concepts and create their logical definitions Relationships and concept definitions Each concept in SNOMED CT is logically defined through its relationships to other concepts Every active SNOMED CT concept except the SNOMED CT Concept Root concept has at least one IS_A relationship to a supertype concept IS_A relationships and defining attribute relationships are known as the defining characteristics of SNOMED CT concepts They are considered defining because they are used to logically represent a concept by establishing its relationships with other concepts This is accomplished by establishing IS_A relationships with one or more defining concepts called supertypes and modeling the difference with those supertypes through defining attributes SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Basic Components Page 3 4 Example Fracture of tarsal bone disorder IS_A Fracture of foot disorder FINDING SITE Bone structure of tarsus body structure ASSOCIATED MORPHOLOGY Fracture morphologic abnormality A relationship is assigned only when that relationship is always known to be true For example Group A Streptococcus causes most cases of Streptococcal pharyn
42. cepts e Mitral valve structure body structure e Uterine structure body structure Morphologic alterations from normal body structures are represented in the sub hierarchy Body structure altered from its original anatomical structure morphologic abnormality SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 4 Examples of Body Structure altered from its original anatomical structure concepts e Adenosarcoma morphologic abnormality e Polyp morphologic abnormality Organism This hierarchy includes organisms of significance in human and animal medicine Organisms are also used in modeling the causes of diseases in SNOMED CT They are important for public health reporting of the causes of notifiable conditions and for use in evidence based infectious disease protocols in clinical decision support systems Sub hierarchies of organism include but are not limited to Animal organism Microorganism organism Plant organism Examples of Organism concepts e Streptococcus pyogenes organism e Texon cattle breed organism e Bacillus anthracis organism e Lichen plant organism Substance The Substance hierarchy contains concepts that can be used for recording active chemical constituents of drug products food and chemical allergens adverse reactions toxicity or poisoning information and physicians and nursing orders Concepts from this hiera
43. cepts modeled with the more specific subtypes of that attribute Role hierarchy used in modeling Clinical Findings ASSOCIATED WITH role hierarchy ASSOCIATED WITH AFTER DUE TO CAUSATIVE AGENT Role hierarchies used in modeling Procedures PROCEDURE DEVICE role hierarchy PROCEDURE DEVICE DIRECT DEVICE INDIRECT DEVICE USING DEVICE USING ACCESS DEVICE PROCEDURE MORPHOLOGY role hierarchy PROCEDURE MORPHOLOGY DIRECT MORPHOLOGY INDIRECT MORPHOLOGY PROCEDURE SITE role hierarchy PROCEDURE SITE PROCEDURE SITE DIRECT PROCEDURE SITE INDIRECT SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 3 4 2 Attributes used to define Clinical Finding concepts NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 1 Approved Clinical Finding attributes summary table Defining Attribute Permissible Values Concepts listed and their descendants FINDING SITE Anatomical structure body structure 91723000 Acquired body structure 280115004 ASSOCIATED MORPHOLOGY Morphologically abnormal structure 49755003 ASSOCIATED WITH Clinical Finding 404684003 Procedure 71388002 Event 272379006 Organism 410607006 Substance 105590001 Physical object 260787004 Physical force 78621006 Pharmaceutical biologic product 373873005 SNOMED CT Concept 138875005 For this concept only the concep
44. ch sub hierarchies as Assessment scales assessment scale which names assessment scales and Tumor staging tumor staging which names tumor staging systems SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 10 Examples of Assessment scales assessment scale concepts e Glasgow coma scale assessment scale e Stanford Binet intelligence scale assessment scale Examples of Tumor staging tumor staging concepts e International Federation of Gynecology and Obstetrics FIGO staging system of gynecological malignancy tumor staging e Dukes staging system tumor staging Linkage concept This hierarchy includes concepts used for linkage The Linkage concept hierarchy contains the sub hierarchies e Link assertion e Attribute Link assertion The Link assertion sub hierarchy enables the use of SNOMED CT concepts in HL7 statements that assert relationships between statements Currently this content supports the UK NHS Connecting for Health requirements for encoding of Statement relationships for the implementation of HL7 Version 3 messaging in the UK realm Examples of Link assertion concepts e Has reason link assertion e Has explanation link assertion Attribute Concepts that descend from this sub hierarchy are used to construct relationships between two SNOMED CT concepts since they indicate the relationship type between those concepts Some attrib
45. cture morphologic abnormality 49755003 Example 1 Specimen from cyst specimen SPECIMEN SOURCE MORPHOLOGY Cyst morphologic abnormality 2 Specimen from wound abscess specimen SPECIMEN SOURCE MORPHOLOGY Abscess of wound morphologic abnormality 4 SPECIMEN SUBSTANCE This attribute names the type of substance of which a specimen is comprised Permissible values include the following concept and its descendants e Substance substance 105590001 Example 1 Mid stream urine sample specimen SPECIMEN SUBSTANCE Urine substance 2 Pancreatic fluid specimen specimen SPECIMEN SUBSTANCE Pancreatic fluid substance 5 SPECIMEN SOURCE IDENTITY This attribute names the type of individual group or physical location from which a specimen is collected Permissible values include the following concepts and their descendants e Person person 125676002 e Family social concept 35359004 e Community social concept 133928008 e Donor qualifier value 261008006 e Device physical object 49062001 e Environment environment 276339004 Examples 1 Catheter tip specimen specimen SPECIMEN SOURCE IDENTITY Catheter tip device physical object 2 Blood specimen from blood donor specimen SPECIMEN SOURCE IDENTITY Blood donor person SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 23 4 6 Attributes used to define Body structure concepts
46. d with SNOMED RT or CTV3 codes e The FullySpecifiedName field appears in both the Concepts Table and the Descriptions Table In the Concepts Table it serves to provide a human readable name for each concept e The ConceptStatus field indicates whether a concept is in active use or retired This field flags concepts that have been retired so that data encoded with these concepts can be properly accessed and retrieved long after it has been coded e The IsPrimitive field indicates whether or not a concept has been flagged as primitive during the modeling process This flag can be useful in advanced applications that take advantage of the description logic features of SNOMED CT A more detailed description of fully defined and primitive concepts can be found in the glossary in Appendix B The Descriptions Table This table relates the various terms used to name a single SNOMED CT concept The Descriptions Table includes the following fields e DescriptionID Each description has a unique DescriptionID which serves as the primary key of this table e DescriptionType This field indicates if the description is one of three types The Fully Specified Name FSN A term that uniquely and unambiguously identifies each concept in a human readable way just as the ConceptID uniquely identifies each term in a machine readable way There is only one Fully Specified Name for each concept in each edition The Preferred Term Intended to repr
47. development of SNOMED CT were complemented with external review e Technical review The technical specifications for SNOMED CT were published for comment on both the SNOMED and NHS websites e Alpha test review Forty two organizations in six countries tested the SNOMED CT alpha test file and completed a structured assessment instrument e Alpha test feedback Debriefing sessions were conducted in the U S in the U K and in Australia at which time test sites shared their positive experiences and recommendations for improvement Early adopters of SNOMED RT were debriefed on their implementation experience in order to identify the key issues to be addressed in the SNOMED CT Technical Implementation Guide Continuous quality improvement Quality improvement is focused on updating the breadth and scope of the content to reflect changes in clinical care and advances in medical science refining the content to deliver greater precision for data collection retrieval and aggregation and enhancing the functionality to serve users better C 3 Acknowledgements Contributors to SNOMED CT SNOMED CT has been created by combining SNOMED RT and a computer based nomenclature and classification known as Clinical Terms Version 3 formerly known as the Read Codes Version 3 which was created on behalf of the U K Department of Health and is Crown copyright The CAP also acknowledges the contributions of e The American Academy of Ophthalmology f
48. dural approach 103379005 DIRECT SUBSTANCE Substance 105590001 Pharmaceutical biologic product 373873005 PRIORITY Priorities 272125009 HAS FOCUS Clinical finding 404684003 Procedure 71388002 HAS INTENT Intents nature of procedure values 363675004 RECIPIENT CATEGORY Person 125676002 Donor for medical or surgical Family 35359004 procedure 105455006 Community 133928008 Group 389109008 REVISION STATUS Primary operation 261424001 Part of multistage procedure 257958009 Revision value 255231005 ROUTE OF ADMINISTRATION Note See explanation below for domain of this attribute Route of administration value 284009009 USING SUBSTANCE Substance 105590001 USING ENERGY Physical force 78621006 1 PROCEDURE SITE This attribute describes the body site acted on or affected by a procedure This attribute subsumes in what is called a role hierarchy explained in Section 4 1 on Role Hierarchies the more specific attributes PROCEDURE SITE DIRECT and PROCEDURE SITE INDIRECT that should be used if possible The anatomical site may be directly acted on PROCEDURE SITE DIRECT or indirectly acted upon PROCEDURE SITE INDIRECT When modeling procedures where the METHOD is Removal action or one of its subtypes e g Excision Surgical biopsy etc removals of the structure itself should use PROCEDURE SITE DIRECT Removals of tissue lesions cysts tumors etc are considered to be removals of the site and should al
49. e hierarchy Permissible values include the following concept and its descendants e Substance substance 105590001 SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 24 Example Naproxen 500mg tablet product HAS ACTIVE INGREDIENT Naproxen substance 2 HAS DOSE FORM This attributes specifies the dose form of a product Permissible values include the following concept and its descendants e Type of drug preparation product 105904009 Example Digoxin 0 1mg capsule product HAS DOSE FORM Capsule dose form product 4 8 Attributes used to define Situation with explicit context concepts NOTE Permissible values include the concepts listed and their descendants Table 4 7 Approved Context attributes summary table Defining Attribute Permissible Values Concepts listed and their descendents ASSOCIATED FINDING Clinical finding 404684003 FINDING CONTEXT Finding context value 410514004 ASSOCIATED PROCEDURE Procedure 71388002 PROCEDURE CONTEXT Context values for actions 288532009 TEMPORAL CONTEXT Temporal context value 410510008 SUB ECT RELATIONSHIP Person 125676002 CONTEXT Context The meaning conveyed by a SNOMED CT concept in a medical record is affected by the context in which it is recorded For instance Breast cancer might be used to indicate a Family history of breast cancer a Past history of breast cance
50. e of completion or status of a Procedure Permissible values include the following concept and its descendants e Context values for actions qualifier value 288532009 Example Operative procedure planned situation ASSOCIATED PROCEDURE Surgical procedure procedure PROCEDURE CONTEXT Planned qualifier value 5 TEMPORAL CONTEXT This attribute indicates the time of occurrence of a Clinical finding or Procedure expressing whether or not the Clinical finding or Procedure was current when the concept was entered into the record Permissible values include the following concept and its descendants e Temporal context value qualifier value 410510008 Example History of hematuria situation ASSOCIATED FINDING Blood in urine finding TEMPORAL CONTEXT n the past qualifier value 6 SUBJECT RELATIONSHIP CONTEXT This attribute is used to specify the relationship between the subject of the record and the subject of the Clinical finding or Procedure being recorded In the example below the subject of the record is the patient and the subject who smokes is the patient s father SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 27 Permissible values include the following concept and its descendants e Person person 125676002 Example Father smokes situation ASSOCIATED FINDING Smoker finding SUBJECT RELATIONSHIP CONTEXT Father person 4 9 At
51. e represented in an application or record structure by combining a header term Family history with the value Diabetes The specific context in this case family history would be represented using the record structure In this case the pre coordinated context dependent concept Family history Diabetes mellitus situation would not be used because the information model has already captured the family history aspect of the diabetes Concepts in the Procedure and Clinical findings hierarchy have a default context of the following SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 3 e The procedure has actually occurred versus being planned or cancelled or the finding is actually present versus being ruled out or considered e The procedure or finding being recorded refers to the patient of record versus for example a family member e The procedure or finding is occurring now or at a specified time versus some time in the past In addition to using the record structure to represent context there is sometimes a need to override these defaults and specify a particular context using the formal logic of the terminology For that reason SNOMED has developed a context model to allow users and or implementers to specify context using the terminology without depending on a particular record structure The Situation with explicit context hierarchy and v
52. ect causative agent of a disease It does not include vectors e g a mosquito that transmits malaria Permissible values include the following concepts and their descendants e Organism organism 410607006 e Substance substance 105590001 e Pharmaceutical biologic product product 373873005 e Physical object physical object 260787004 e Physical force physical force 78621006 e SNOMED CT Concept 138875005 For this concept only the concept and not all of its descendents is allowed as a value SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 6 Examples 1 Bacterial endocarditis disorder CAUSATIVE AGENT Bacterium organism 2 Fentanyl allergy disorder CAUSATIVE AGENT Fentanyl substance 3 Electrical burn of skin disorder CAUSATIVE AGENT Electricity physical force 4 SEVERITY This attribute can be used to represent the level of severity for a Clinical finding concept Use of the SEVERITY attribute is sometimes relative It assumes that the same weighting is used for all Clinical Findings Disorders to which this attribute is applied which is not necessarily the case For instance severe could be interpreted differently for the following set of values Mild Moderate Severe Minimal Mild Moderate Severe Very Severe Also the decision of when a finding or disorder is mild moderate or severe is somewhat subjective The attr
53. ermissible values include the following concept and its descendants e Morphologically abnormal structure morphologic abnormality 49755003 DIRECT MORPHOLOGY This attribute describes the morphology to which the procedure is directed Permissible values include the following concept and its descendants e Morphologically abnormal structure morphologic abnormality 49755003 Example Excision of benign neoplasm procedure METHOD Excision action qualifier value DIRECT MORPHOLOGY Neoplasm benign morphologic abnormality INDIRECT MORPHOLOGY This attribute represents a morphology that is acted upon but is not the direct target of the action being performed i e the procedure s method acts directly on something else such as a device substance or anatomical structure Permissible values include the following concept and its descendants e Morphologically abnormal structure morphologic abnormality 49755003 Example Removal of mesh from wound procedure METHOD Removal action qualifier value DIRECT DEVICE Mesh physical object INDIRECT MORPHOLOGY Wound morphologic abnormality 3 METHOD This attribute represents the action being performed to accomplish the procedure It does not include the access e g percutaneous approach e g translumbar equipment e g sutures or physical forces e g laser energy Permissible values include the following concept and its descendants e Action qualifier value 129264002
54. es and Clinical findings SUBJECT RELATIONSHIP CONTEXT and TEMPORAL CONTEXT 1 ASSOCIATED FINDING This attribute links concepts in the Situation with explicit context hierarchy to their related Clinical finding It specifies the Clinical finding concept whose context is being modified Permissible values include the following concept and its descendants e Clinical finding finding 404684003 Example Family history of stroke situation ASSOCIATED FINDING Cerebrovascular accident disorder 2 FINDING CONTEXT This attribute indicates whether the associated Clinical finding is known or unknown and whether it is present or absent Permissible values include the following concept and its descendants e Finding context value qualifier value 410514004 SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 26 Example No cough situation ASSOCIATED FINDING Cough finding FINDING CONTEXT Known absent qualifier value 3 ASSOCIATED PROCEDURE This attribute links concepts in the Situation with explicit context hierarchy to concepts in the Procedure hierarchy for which there is additional specified context Permissible values include the following concept and its descendants e Procedure procedure 71388002 Example Operative procedure planned situation ASSOCIATED PROCEDURE Surgical procedure procedure 4 PROCEDURE CONTEXT This attribute indicates the degre
55. esent the common way a concept is expressed in natural language by clinicians In many cases itis a shortened version of the Fully Specified Name Synonyms Other terms that can be used to name a concept The large numbers of synonyms in SNOMED CT provide flexibility of expression e LanguageCode This field in the Descriptions Table associates each description with a particular language or dialect such as UK English Spanish etc See the Technical Reference Guide for more information about the Descriptions Table SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Page 6 3 The Relationships Table This table contains the relationships between SNOMED CT concepts A Relationship in the table is stored as a combination of three concepts in the order ConceptID1 RelationshipType ConceptID2 This is represented in the table by the following fields e RelationshipID The RelationshipID uniquely identifies each set of three concepts in a relationship and serves as the primary key of this table e ConceptID1 The first concept in the relationship e RelationshipType This is the type of relationship either the IS_A relationship or an attribute or a Historical or Additional relationship that exists between two concepts e ConceptlD2 The target concept in the relationship Either the Parent concept in an IS_A relationship or the concept th
56. for a particular International Edition A Subset is a value added feature of SNOMED CT Subsets provide important information for the use and implementation of SNOMED CT The fact that a SNOMED CT Component belongs to a particular subset provides information above and beyond the Component itself SNOMED CT is a large terminology and subsets can define portions of the terminology for use by specific audiences For example a UK dialect subset for English may direct the user to descriptions for UK terms rather than all descriptions for English Note that it is up to the implementer to determine if a subset is used dynamically or statically and whether the subset contents are given precedence or used exclusively Refer to the SNOMED CT Technical Implementation Guide for more information Note that Subsets are not necessarily mutually exclusive The contents of Subsets may overlap Subset table and file structures A common file structure is used for all Subsets This approach simplifies the release structure and installation process for all SNOMED users Subsets are released using two tables e Subsets Table SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Page 6 5 Each row in this table describes one release of a Subset This table includes SNOMED CT Subsets that are packaged together in the Subset Members table e Subset Members Table
57. ge 6 4 disease processes introduction of new drugs investigations therapies and procedures and new threats to health as well as proposals and work provided by SNOMED partners and licensees The Component History includes any changes to SNOMED CT Components Concepts Descriptions Subsets Cross Maps Significant changes generally require retirement of the component and addition of replacement component s The retirement and addition are recorded in the history records Changes designated as minor require only a history record to record the change History Mechanism The history mechanism involves the following tables e Component History Table e Component History References Table 6 4 SNOMED CT Subsets Introduction A Subset refers to a set of Concepts Descriptions or Relationships that are appropriate to a particular language dialect country specialty organization user or context In its simplest form the Subset Mechanism is a list of SNOMED identifiers SCTIDs Each SCTID refers to one component of SNOMED CT that is a member of the Subset called a Subset Member As an analogy think of SNOMED CT as a book A Subset is like an index entry pointing to a set of pages relevant to a particular topic The Subset Mechanism may be used to derive tables that contain only part of SNOMED CT In some cases these derived tables may also be centrally distributed e g a release table containing only Descriptions
58. gitis However a small percentage of these cases are caused by other species of Streptococcus Consequently when defining the concept Streptococcal sore throat disorder Streptococcus Group A was not chosen as a value for the CAUSATIVE AGENT attribute A more general concept Streptococcus organism was selected IS_A relationships IS_A relationships are also known as Supertype Subtype relationships or Parent Child relationships IS_A relationships are the basis of the SNOMED CT s hierarchies Example Disorder of foot disorder IS A Injury of foot disorder IS_A Fracture of foot disorder IS_A Open fracture of foot disorder A concept can have more than one IS_A relationship to other concepts In that case the concept will have parent concepts in more than one sub hierarchy of a top level hierarchy Subtype relationships can be multi hierarchical Disorder of foot Cellulitis of foot Figure 3 2 Example IS_A relationships Attribute relationships Attributes relate two concepts and establish the type of relationship between them Together with IS_A relationships they are considered defining characteristics since they allow the logical representation of the meaning of a concept by establishing its relationships with other concepts A logical concept definition includes one or more SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Basic Components
59. he use of rules to identify subset members and by the direct identification of subset members SNOMED CT Namespace Identifier This identifier is issued to an organization that wants to create SNOMED CT identifiers such as Subset Identifiers A Namespace Identifier may also be issued separately from the Subset Kit Additional Documentation Documentation is also provided with the following Allergen Subset Anatomic Pathology Subset Canonical Table Developer Toolkit Namespace Identifier SNOMED CT Encoded CAP Cancer Checklists CLUE Browser documentation is provided in CLUE files The CLUE Browser is Copyright of The Clinical Information Consultancy SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Introduction Page 1 1 1 Introduction 1 1 Purpose This document describes the content structure and terminology of SNOMED CT Itis intended to provide new as well as experienced users with an overview and illustrations of SNOMED CT s capabilities and uses from a content perspective As such it explains the content and the principles used to model the terminology 1 2 Who should read this guide The intended audience for the User Guide includes clinical personnel business directors software product managers and project leaders who are involved in the acquisition implementation and use of SNOMED CT and SNOMED CT enabled applications in their organizations While information
60. ibute cannot be relied on to retrieve all severe findings or disorders in SNOMED CT Current permissible values include e Descendants of Severities qualifier value 272141005 which include but are not limited to Mild qualifier value Moderate severity modifier qualifier value Severe severity modifier qualifier value 5 CLINICAL COURSE This attribute is a new defining attribute for the January 2007 release It is intended to represent both the course and onset of a disease It replaces the earlier attributes COURSE and ONSET Many conditions with an acute onset also have an acute course Some of the permissible values for the retired attributes COURSE and ONSET have been merged to allow a more general meaning This general meaning is now represented using the attribute CLINICAL COURSE Permissible values include the following concept and its descendants e Courses qualifier value 288524001 SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 7 Examples 1 Acute amebic dysentery disorder CLINICAL COURSE Sudden onset AND OR short duration qualifier value 2 Chronic fibrosing pancreatitis disorder CLINICAL COURSE Chronic clinical course qualifier value NOTE The attributes ONSET and COURSE have been retired for the January 2007 release While ONSET was intended to specify the period of onset or the temporal pattern of presentation for
61. ifies a description Multiple descriptions might be associated with a concept identified by its ConceptID Example Some of the descriptions associated with ConceptID 22298006 e Fully Specified Name Myocardial infarction disorder DescriptionID 751689013 e Preferred term Myocardial infarction DescriptionID 37436014 e Synonym Cardiac infarction Description ID 37442013 e Synonym Heart attack DescriptionID 37443015 e Synonym Infarction of heart Description ID 37441018 Each of the above descriptions has a unique DescriptionID and all of these descriptions are associated with a single Concept and the single ConceptID 22298006 Types of descriptions Fully Specified Name FSN Each concept has one unique FSN intended to provide an unambiguous way to name a concept The purpose of the FSN is to uniquely identify a concept and clarify its meaning not necessarily to present the most commonly used or natural phrase for that concept Each FSN ends with a semantic tag in parentheses at the end of the concept The semantic tag indicates the semantic category to which the concept belongs e g Disorder Organism Person etc For example Hematoma morphologic abnormality is a FSN that represents the description of what the pathologist sees at the tissue level whereas Hematoma disorder is a FSN which indicates the concept that would be used to code the clinical diagnosis of a hematoma by a general practitioner
62. ify the meaning of a Clinical finding or Procedure in a way that changes the axis or hierarchy of the concept The resulting modified concept is not a subtype of the original concept to which the attribute was applied This is not the case with the other attributes in SNOMED CT Although the non context modifying attributes also change the meaning of concept to which they are applied the resulting concept is still a subtype of the original concept For instance if the concept Fine needle biopsy procedure is given the non context modifying attribute PROCEDURE SITE and a value Urinary bladder structure body structure the resulting concept Fine needle biopsy of urinary bladder procedure is still a subtype of the original concept Fine needle biopsy procedure However the concept Urine protein test not done situation has the context modifying attribute PROCEDURE CONTEXT and a value of Not done qualifier value and the resulting concept is not a subtype of Urine protein test procedure Overview of the context attributes Of the six attributes applied to concepts in the Situation with explicit context hierarchy two are used only in representing the context in which a Clinical finding is recorded ASSOCIATED FINDING and FINDING CONTEXT two are used only in representing the context in which a Procedure is recorded ASSOCIATED PROCEDURE and PROCEDURE CONTEXT and two attributes are used in representing the context of both Procedur
63. indings not elsewhere classified V A concept starting with V identifies concepts contained in ICD 9 Supplementary classification of factors influencing health status and contact with health services V codes and ICD 10 chapter XXI Factors influencing health status and contact with health services Z codes M A concept starting with M identifies Morphology of Neoplasm concepts present in ICD9 and ICD 10 SO A concept starting with SO identifies the concepts contained in OPCS 4 Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures 4th Revision chapter Z subsidiary classification of sites of operation in CTV3 Q A concept starting with Q identifies temporary qualifying terms inherited from CTV3 SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Glossary Page B 1 Appendix B Glossary Attribute Attribute value pair Browser Check digit Component Concept Concept equivalence ConceptID Concepts Table Core Cross Map Express characteristics of concepts SNOMED CT concepts form relationships to other SNOMED CT concepts through attributes Example FINDING SITE All of the attributes used in modeling SNOMED CT concepts are themselves SNOMED CT concepts and can be found in the Linkage concept hierarchy The combination of an attribute with a value that is appropriate for that attribute
64. ion x ce 2e vcseccagstecstasiclede es ieae iene tteaehaaneaadslateatg heeded 1 2 2 SOVEIMIOW seio E E A EN 2 1 2 1 What is SINCE Bat ie fa estar a cece eased cheater Some Maknh ces inaac Msaqioaae eacun aeateeacege 2 1 2 2 SINOMED C RO 4 alice ctereti the oct satekcatuacnc E paddae hs ait eee aoecteaatuau teal 2 1 3 Basic Components of SNOMED CT oi ics cccccc cessescccascdeceengesqactveyesecadetyscbeteeneteieeyans 3 1 3 1 COMGC DIS a s3c chris aah Sis ion reine E aetna A E E T E 3 1 3 2 Description Si ineen paveebet tee n aaa E E EEEE ARAA EAEE E tan eak 3 2 3 3 aeoaea o E TA E A T 3 3 4 Attributes Used in SNOMED CT ooo eee ee cece ee eeeceeeeeteeeeeeeeeeeeeeeeeeaaeeeeeeaeaeeeeas 4 1 4 1 IATFODUCH ON versa scectceesstaedavieettancasivevsazteasezcaiazectensecides TET AE 4 1 4 2 Attributes used to define Clinical Finding Concepts cccceeeeeeeeeeeteeeeeees 4 3 4 3 Attributes used to define Procedure CONCEPTS eeeeeeseeeeeeeeeeeeeeeeeeeeaes 4 10 4 4 Attributes used to define Measurement Procedure concepts 0 4 19 4 5 Attributes used to define Specimen Concepts cccceceeeeeeeeeeeeeeeeneeeeeees 4 21 4 6 Attributes used to define Body structure Concepts ecceceeeeeeeeeeeeeneees 4 23 4 7 Attributes used to define Pharmaceutical Biologic Product concepts 4 23 4 8 Attributes used to define Situation with explicit context concepts 4 24 4 9 Attributes used to define Event concepts
65. ized to execute an action USING DEVICE is used when the device is actually used to carry out the action that is the focus of the procedure If the device is simply the means to access the site of the procedure then USING ACCESS DEVICE is used instead of USING DEVICE Permissible values include the following concept and its descendants e Device physical object 49062001 Example Core needle biopsy of larynx procedure METHOD Biopsy action qualifier value USING DEVICE Core biopsy needle device physical object PROCEDURE SITE DIRECT Laryngeal structure body structure NOTE USING DEVICE replaces the attribute USING which has been retired for the January 2007 release The retired attribute USING allowed values that included descendents of Physical force physical force 78621006 which are not actually devices Additionally the new DEVICE attributes are intended to clarify the inconsistency that existed over when to use the attribute USING versus ACCESS INSTRUMENT versus ACCESS particularly for Endoscopic procedures SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 15 USING ACCESS DEVICE This attribute specifies the instrument or equipment used to access the site of a procedure Permissible values include the following concept and its descendants e Device physical object 49062001 Example Arthroscopic synovial biopsy procedure METHOD Biopsy ac
66. ment Extensions are complements to a released version of SNOMED CT Extensions are components that are created in accordance with the data structures and authoring guidelines applicable to SNOMED CT SNOMED CT concepts are either primitive or fully defined Fully defined concepts can be differentiated from their parent and sibling concepts by virtue of their relationships Primitive concepts do not have the unique relationships needed to distinguish them from their parent or sibling concepts A concept is primitive when its modeling attributes and parents does not fully express its meaning A description that names a Concept in a manner intended to be unambiguous An ordered organization of concepts General concepts are at the top of the hierarchy at each level down the hierarchy concepts become increasingly specialized SNOMED CT concepts are arranged into Top level hierarchies Each of these hierarchies subdivides into smaller sub hierarchies Concepts are related by IS_A relationships to their more general parent concepts directly above them in a hierarchy There is one concept from which the Top level hierarchies descend called SNOMED CT concept or the Root concept SNOMED CT includes some information about the history of changes to concepts and descriptions For purposes of SNOMED CT translations a language is a vocabulary and grammatical form that has been allocated an ISO639 1 language code See also Dialect SN
67. oard consists of clinical content experts and medical informatics experts half of whom come from the United Kingdom s National Health Service In addition liaisons from numerous associations reflect the vision of an integrated clinical vocabulary Participation of liaisons allows scientific input from a range of clinical specialties and government agencies SNOMED Working Groups The SNOMED Working Groups utilize the quality standards to structure terminology related to specific clinical domains The Working Group for Nursing for example is comprised of domain experts external to CAP and supported by the SNOMED International operations team The Working Groups advise the SNOMED Standards Board regarding scope of coverage creation of new content concept modeling and scientific accuracy of the concepts and terms within a specific clinical domain SNOMED Team Operations Terminology Modelers Consulting and Licensing SNOMED International brings extensive experience in development and use of SNOMED Its multi disciplinary team in the US and UK comprises individuals with backgrounds in medical informatics clinical medicine laboratory medicine pharmacy nursing and education as well as database services SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Guiding Principles and Acknowledgements Page C 3 Extent of review The quality processes used in the
68. obtained the procedure used to collect the specimen the source from which it was collected and the substance of which it is comprised Examples of Specimen concepts e Specimen from prostate obtained by needle biopsy specimen e Urine specimen obtained by clean catch procedure specimen e Calculus specimen specimen e Cerebroventricular fluid cytologic material specimen Physical object Concepts in the Physical object hierarchy include natural and man made objects One use for these concepts is modeling procedures that use devices e g catheterization Examples of Physical object concepts e Military vehicle physical object e Implant device physical object e Artificial kidney device physical object e Latex rubber gloves physical object e Book physical object e Pressure support ventilator physical object e Vena cava filter physical object Physical force The concepts in the Physical force hierarchy are directed primarily at representing physical forces that can play a role as mechanisms of injury Examples of Physical force concepts e Spontaneous combustion physical force e Alternating current physical force e Friction physical force Event The Event hierarchy includes concepts that represent occurrences excluding procedures and interventions SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 9 Examples of Event conce
69. ology Considerations 6 1 Introduction The structure and technology behind SNOMED CT enable organizations to implement it and integrate it into their own clinical and business processes and applications SNOMED CT offers additional capabilities to facilitate customization of an implementation to meet the unique requirements of an organization This section provides an introduction to SNOMED CT structure and technology highlighting its core and extended capabilities This overview is intended to provide project managers and others involved with SNOMED CT implementations a better understanding of technology requirements and support considerations for SNOMED CT implementation and maintenance Topics addressed include e SNOMED CT data structure SNOMED CT data components and their relationships including the core table structure as well as History Subsets Cross Mapping Extensions e SNOMED CT applications and services Detailed information for each topic is available in the SNOMED CT Technical Reference Guide TRG Technical Implementation Guide TIG Developer Toolkit and other related SNOMED CT reference documents See the Inventory of Documentation section of this guide for descriptions of the content and target audiences for each available document 6 2 SNOMED CT tables SNOMED CT is distributed as a set of tab delimited text files that can be imported into a relational database The three tables shown below the Concepts ta
70. or FINDING SITE Defining attributes in SNOMED CT are assigned to the hierarchies where retrieval of clinical data is most useful and relevant e g Procedure Clinical finding Pharmaceutical Biologic product Situation with explicit context Event and Specimen SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 2 In addition LATERALITY is a defining attribute applied to Body structure concepts Other hierarchies such as Social context Substance Organism Observable entity and Physical object do not take attributes and instead are considered supporting hierarchies Concepts from the supporting hierarchies can serve as the attribute values for the concept definitions of the main hierarchies This section of the SNOMED CT User Guide describes the approved attributes used in SNOMED CT Criteria have been used to evaluate approved attributes and to determine whether they should be added to the terminology There are many other attributes in SNOMED subtypes of Unapproved attribute attribute which have not yet been evaluated thoroughly and approved for use Role Hierarchies in SNOMED CT Selected SNOMED CT attributes have a hierarchical relationship to one another known as role hierarchies In a role hierarchy one general attribute is the parent of one or more specific subtypes of that attribute Concepts defined using the more general attribute can inherit con
71. or the concept Pneumonia disorder the ConceptID is 233604007 A table that includes all SNOMED CT concepts Each concept is represented by a row A SNOMED CT Component released by SNOMED International A Cross Map links a single SNOMED CT concept to one or more codes in a target classification such as ICD 9 CM or terminology Each Cross Map is represented as a row in the Cross Maps Table SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Glossary Page B 2 CTV3ID Description DescriptionID Descriptions Table Dialect Extension Fully defined concept Fully Specified Name FSN Hierarchy History Mechanism Language A five character code allocated to a concept or term in CTV3 For data compatibility and mapping purposes SNOMED CT concepts include a record of the corresponding concept codes from the Clinical Terms Version 3 CTV3 previously known as Read Codes and SNOMED RT The human readable phrases or names associated with SNOMED CT concepts All of the concept descriptions in SNOMED CT are listed in the Descriptions Table An SCTID that uniquely identifies a Description Refer to the SNOMED Technical Reference Guide for a full explanation of how this identifier is structured A table including all SNOMED CT descriptions A language modified by the vocabulary and grammatical conventions applied in a particular geographical or cultural environ
72. or the ophthalmology related portions of this work e SNODENT the Systematized Nomenclature of Dentistry copyright 1998 American Dental Association Used with permission e SNOVET the Systematized Nomenclature of Veterinary Medicine copyright 1982 1993 American Veterinary Medical Association Used with permission e LOINC the Logical Observation Identifier Names and Codes copyright 1995 2005 Regenstrief Institute LOINC Committee All rights reserved e NANDA Taxonomy II copyright 2005 2006 NANDA International All rights reserved e The Perioperative Nursing Data Set PNDS copyright 2002 AORN Inc All rights reserved e The Omaha System copyright 1992 Martin and Associates Used with permission e The Clinical Care Classification copyright 2004 V K Saba Used with permission SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Guiding Principles and Acknowledgements Page C 4 e The Nursing Interventions Classification NIC copyright 2004 Mosby Inc and the Center for Nursing Classification and Clinical Effectiveness at the University of lowa College of Nursing Used with permission e The Nursing Outcomes Classification NOC copyright 2004 Mosby Inc and the Center for Nursing Classification and Clinical Effectiveness at the University of lowa College of Nursing Used with permission e This work contains material from the AJCC Cancer Staging Man
73. owing concepts and their descendants e Anatomical structure body structure 91723000 e Acquired body structure body structure 280115004 Examples 1 Removal of catheter from brachial vein procedure METHOD Removal action qualifier value DIRECT DEVICE Catheter device physical object PROCEDURE SITE INDIRECT Structure of brachial vein body structure 2 Removal of calculus of urinary bladder procedure METHOD Removal action qualifier value DIRECT MORPHOLOGY Calculus morphologic abnormality PROCEDURE SITE INDIRECT Urinary bladder structure body structure SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 12 2 PROCEDURE MORPHOLOGY This attribute is used to specify the morphology or abnormal structure involved in the procedure This attribute subsumes in what is called a role hierarchy explained in the section 4 on Role Hierarchies the more specific attributes DIRECT MORPHOLOGY and INDIRECT MORPHOLOGY that should be used if possible DIRECT MORPHOLOGY is used when the procedure method acts directly on the morphologic abnormality INDIRECT MORPHOLOGY is used when the procedure method acts directly on something else e g a device substance or anatomical structure that is associated with the morphologic abnormality The more general attribute PROCEDURE MORPHOLOGY is used when defining general concepts that subsume both kinds of sub concepts P
74. pts e Flood event e Bioterrorist attack event e Earthquake event Environments and geographic locations The Environments and geographic locations hierarchy includes types of environments as well as named locations such as countries states and regions Examples of Environments and geographic locations concepts e Canary islands geographic location e California geographic location e Rehabilitation department environment e Intensive care unit environment Social context The Social context hierarchy contains social conditions and circumstances significant to healthcare Content includes such areas as family status economic status ethnic and religious heritage life style and occupations These concepts represent social aspects affecting patient health and treatment Some sub hierarchies of Social context and concepts typical of those sub hierarchies are shown in the following examples Examples e Ethnic group ethnic group Afro Caribbean ethnic group Estonians ethnic group e Occupation occupation Bank clerk occupation Carpenter general occupation e Persons person Employer person Boyfriend person Caregiver person e Religion philosophy religion philosophy Hinduism religion philosophy Orthodox Christian religion religion philosophy e Economic status social concept Middle class economic status social concept Staging and scales This hierarchy contains su
75. r or a Current diagnosis of breast cancer Each of these three meanings differs in regard to the context in which breast cancer is being described Family history of breast cancer refers to breast cancer occurring in a family member of a patient Past history of breast cancer indicates that the breast cancer occurred in the patient at some time in the past and it is not necessarily present now Current diagnosis of breast cancer indicates that the breast cancer is present now and in this patient Default context When a SNOMED CT concept appears in a record without any explicitly stated context then that concept is considered to have a soft default context The soft default context for a Clinical finding means that the finding has actually occurred vs being absent it is occurring to the subject of record the patient and it is occurring currently or at a stated past time SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 25 The soft default context for a Procedure means that the procedure was completed was performed on the subject of record the patient and was done in the present time or at a stated past time Axis modifiers The six attributes used for modeling context dependent concepts in SNOMED CT permit representation of various contexts When used to represent something other than the soft default context these context modifying attributes mod
76. rchy represent general substances and chemical constituents of Pharmaceutical biologic product product which are in a separate hierarchy However sub hierarchies of Substance also include but are not limited to Body substance substance concepts to represent body substances Dietary substance substance Diagnostic substance substance Examples of Substance concepts e Insulin substance e Methane substance e Chromatin substance e Dental porcelain material substance e Albumin substance e Endorphin substance e Acetaminophen substance Pharmaceutical biologic product The Pharmaceutical biologic product hierarchy is separate from the Substance hierarchy This hierarchy was introduced as a top level hierarchy in order to clearly distinguish drug products products from their chemical constituents substances SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 5 It contains concepts that represent the multiple levels of granularity required to support a variety of uses cases such as computerized provider order entry CPOE e prescribing decision support and formulary management The levels of drug products represented in the core include Virtual Medicinal Product VMP Virtual Therapeutic Moiety VTM and Product Category Additionally US and UK drug extensions are available which represent Actual Medicinal Products AMPs Virt
77. rdized information improves analysis SNOMED CT provides a standard for Clinical information Software applications can use the concepts hierarchies and relationships as a common reference point for data analysis SNOMED CT serves as a foundation upon which health care organizations can develop effective analysis applications to conduct outcomes research evaluate the quality and cost of care and design effective treatment guidelines Standardized terminology can provide benefits to clinicians patients administrators software developers and payers A clinical terminology can aide in providing health care providers with more easily accessible and complete information pertaining to the health care process medical history illnesses treatments laboratory results etc and thereby result in improved patient outcomes A clinical terminology can allow a health care provider to identify patients based on certain coded information in their records and thereby facilitate follow up and treatment SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Basic Components Page 3 1 3 Basic Components of SNOMED CT 3 1 Concepts In the context of this document a concept is a clinical meaning identified by a unique numeric identifier ConceptID that never changes Concepts are represented by a unique human readable Fully Specified Name FSN The concepts are formally defined in terms of their relation
78. re REVISION STATUS Primary operation qualifier value 2 Revision of knee arthroplasty procedure REVISION STATUS Revision value qualifier value 13 ROUTE OF ADMINISTRATION This attribute was added in the January 2006 release to allow a procedure to be more fully modeled so that its definition includes the route of administration of a given substance The domain for this attribute is not the entire Procedure hierarchy but rather the subhierachy of concepts that descend from Administration of treatment via specific route procedure 394898006 Permissible values include the following concept and its descendants SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 18 e Route of administration value qualifier value 284009009 Example Inhaled drug administration procedure ROUTE OF ADMINISTRATION By inhalation route qualifier value 14 USING SUBSTANCE This is a new attribute introduced in the January 2007 release This attribute describes the Substance used to execute the action of a procedure but it is not the substance on which procedure s method directly acts the DIRECT SUBSTANCE Permissible values include the following concepts and their descendants e Substance substance 105590001 Example Contrast radiography of esophagus procedure METHOD Radiographic imaging action qualifier value PROCEDURE SITE DIRECT Esophageal structure body
79. re to e Provide a structure where these Extensions maintain unique identification across organizations for data transmission and sharing but share a common structure for ease in application development and so that subsets can be constructed over a combination of core and extension content e Define a structure so that it is easy to submit include use and migrate terminology developed as part of an extension into the core content When content overlaps the scope of SNOMED CT it should be submitted to the SNOMED International team for consideration for the core content so that other SNOMED CT licensees can also take advantage of this work The preferred way to do this is by the web based SNOMED CT Request Submission system Another technique is to assemble the terminology into an extension so it can be transferred Using the extension structure can also help organizations transfer responsibility for terminology not only to SNOMED International but also to another organization as appropriate 6 7 SNOMED CT applications and services SNOMED Clinical Terms is a terminological resource that can serve many roles in healthcare software applications The SNOMED International organization supplies content that can be loaded into these applications but it does NOT supply any of the software itself User requirements for these software applications will vary according to way in which they are used Healthcare software applications usually addre
80. rrect method with the correct site In the example below the role groups clarify that there is exploration of the bile duct and excision of the gall bladder Without role groups the four attributes would be ungrouped and it would be unclear whether the excision was of the bile duct or of the gall bladder Cholecystectomy and exploration of bile duct METHOD Exploration R ole group PROCEDURE SITE DIRECT Bile duct structure METHOD Excision PROCEDURE SITE DIRECT Gall bladder structure Role group Figure 4 2 Example Cholecystectomy and exploration of bile duct SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 1 5 Hierarchies SNOMED CT concepts are organized into hierarchies The SNOMED CT Concept is the Root concept The SNOMED CT Concept subsumes is the supertype of the top level concepts and all the concepts beneath them their subtypes As the hierarchies are descended the concepts within them become increasingly specific or granular A brief description of the content in each hierarchy is given below Subtype or child concepts are the descendent concepts of Supertype or parent concepts Example Streptococcal arthritis disorder is a subtype of Bacterial arthritis disorder Supertype concepts are the ancestor concepts of Subtype concepts Example Bacterial
81. se 2002 2007 College of American Pathologists Overview Page 2 1 2 Overview 2 1 What is SNOMED CT SNOMED Clinical Terms SNOMED CT is a comprehensive clinical terminology that provides clinical content and expressivity for clinical documentation and reporting It can be used to code retrieve and analyze clinical data SNOMED CT resulted from the merge of SNOMED Reference Terminology SNOMED RT developed by the College of American Pathologists CAP and Clinical Terms Version 3 CTV3 developed by the National Health Service NHS of the United Kingdom The terminology is comprised of concepts terms and relationships with the objective of precisely representing clinical information across the scope of health care Content coverage is divided into hierarchies which include e Clinical finding e Physical force e Procedure e Event e Observable entity e Environments geographical locations e Body structure e Social context e Organism e Situation with explicit context e Substance e Staging and scales e Pharmaceutical biologic product e Linkage concept e Specimen e Qualifier value e Special concept e Record artifact e Physical object 2 2 SNOMED CT uses Health care software applications focus on collection of clinical data linking to clinical knowledge bases information retrieval as well as data aggregation and exchange Information may be recorded in different ways at different times and sites of care Standa
82. ships with other concepts These logical definitions give explicit meaning which a computer can process and query on Every concept also has a set of terms that name the concept in a human readable way Concept granularity Granular means specific or particular Concepts represent various levels of clinical detail Concepts can be very general or they can represent increasingly specific levels of detail also referred to as increasing granularity Multiple levels of granularity improve the capability to code clinical data at the appropriate level of detail 4 Procedure IS_A K in on Aggregate level en node ISA Biopsy of lymph node IS_A A P f lymph of lymph node Clinical detail IS_A Poa biopsy on node Figure 3 1 Multiple levels of granularity level Concepts and identifiers SNOMED CT concepts have unique numeric identifiers called ConceptIDs ConceptIDs do not contain hierarchical or implicit meaning The numeric identifier does not reveal any information about the nature of the concept Example 55679008 is the ConceptlID for the concept Peribronchial pneumonia disorder SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Basic Components Page 3 2 3 2 Descriptions Concept descriptions are the terms or names assigned to a SNOMED CT concept Term in this context means a phrase used to name a concept A unique DescriptionID ident
83. so use PROCEDURE SITE SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 11 DIRECT Removals of devices calculi thrombi foreign bodies and other non tissue entities from the structure should use PROCEDURE SITE INDIRECT Permissible values include the following concepts and their descendants e Anatomical structure body structure 91723000 e Acquired body structure body structure 280115004 PROCEDURE SITE DIRECT This attribute is used when the action of the procedure is directly aimed at an anatomical structure or site rather than at something else Such as a device located there Permissible values include the following concepts and their descendants e Anatomical structure body structure 91723000 e Acquired body structure body structure 280115004 Examples 1 Amputation of the foot procedure METHOD Amputation action qualifier value PROCEDURE SITE DIRECT Foot structure body structure 2 Biopsy of femur procedure METHOD Biopsy action qualifier value PROCEDURE SITE DIRECT Bone structure of femur body structure PROCEDURE SITE INDIRECT This attribute describes the anatomical site which is acted upon but is not the direct object of the procedure The site is indirectly acted on by the procedure Usually in these procedures there is another value that is the direct object of the action Permissible values include the foll
84. ss a particular set of requirements associated with one or more clinical and or business processes Detailed requirements for integrating SNOMED CT into a particular application inevitably depend upon intended uses the perceptions of users and the technical environments in which they are implemented The following examples illustrate a few possible types of implementation e ASNOMED CT enabled clinical record system incorporating clinical data entry decision support links to knowledge bases sophisticated analysis order report message interfaces support for record communication or sharing etc e A data warehouse storing and analyzing records expressed with SNOMED CT encoded concepts SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Structure and Technology Considerations Page 6 7 e A diagnostic departmental system sending reports that include SNOMED CT encoded concepts to other systems e A hand held data collection device used for input of a limited range of frequently used coded concepts e A decision support system using SNOMED CT concepts to represent guidelines and protocols for distribution to other systems e A system designed to enable the creation of queries for use in analysis of data held by various other systems some of which contain SNOMED CT encoded data e Acoding system mapping SNOMED CT encoded concepts entered manually or read from an electronic record to
85. supplemented by feedback from users involved in adoption of SNOMED Clinical Terms Parallel to domain specialist review U S and U K editors continue to review and edit content as needed SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Guiding Principles and Acknowledgements Page C 2 Expert input The following entities and groups contribute to SNOMED CT content Table C 1 Roles of college committees staff and volunteers in development and review of SNOMED Entity Role SNOMED International Authority Within the governance structure of the College of American Pathologists CAP the SNOMED International Authority has the direct responsibility for terminology related activities It establishes strategic direction for SNOMED s medical terminology activities strategic alliances and support requirements The Authority consists of CAP leadership the SNOMED Scientific Director key internal staff directors and external stakeholders from within and outside the U S These individuals bring expertise in the following areas national and international standards medical informatics software database licensing biotechnology clinical and academic medicine and managed care SNOMED International Standards Board The SNOMED International Standards Board guides the scientific direction editorial processes and scientific validity of the terminology The Standards B
86. t and not all of its descendents is allowed as a value CAUSATIVE AGENT Organism 410607006 Substance 105590001 Physical object 260787004 SNOMED CT Concept 138875005 Physical force 78621006 Pharmaceutical biologic product 373873005 For this concept only the concept and not all of its descendents is allowed as a value DUE TO Clinical Finding 404684003 Event 272379006 AFTER Clinical Finding 404684003 Procedure 71388002 SEVERITY Severities 272141005 CLINICAL COURSE Courses 288524001 EPISODICITY Episodicities 288526004 INTERPRETS Observable entity 363787002 Evaluation procedure 386053000 Laboratory Procedure 108252007 HAS INTERPRETATION Findings values 260245000 Result comments 281296001 PATHOLOGICAL PROCESS Autoimmune 263680009 HAS DEFINITIONAL MANIFESTATION Clinical finding 404684003 OCCURRENCE Periods of life 282032007 FINDING METHOD Procedure 71388002 FINDING INFORMER Performer of method person 420158005 Provider of history other than subject person 420058008 Subject of record person 410604004 Subject of record or other provider of history person 419358007 SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 4 1 FINDING SITE This attribute specifies the body site affected by a condition Permissible values include the following concepts and their
87. tion It is used when an essential feature of a disorder is a clinical finding It can only be applied to disorders Permissible values include the following concept and its descendants e Clinical finding finding 404684003 11 OCCURRENCE This attribute refers to the specific period of life during which a condition first presents This does not mean the condition cannot persist beyond the period of life in which it first presents Permissible values include the following concept and its descendants e Periods of life qualifier value 282032007 Example Childhood phobic anxiety disorder disorder OCCURRENCE Childhood qualifier value SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 9 12 13 FINDING METHOD This attribute specifies the means by which a clinical finding was determined This attribute is frequently used in conjunction with FINDING INFORMER Findings that specify that they were determined by examination of the patient e g On examination ankle clonus finding should have a value for both FINDING METHOD and FINDING INFORMER Permissible values include the following concept and its descendants e Procedure procedure 71388002 Example Finding by palpation finding FINDING METHOD Palpation procedure FINDING INFORMER This attribute specifies the person or other entity from which the clinical finding information was obtained This at
88. tion qualifier value USING ACCESS DEVICE Arthroscope device physical object PROCEDURE SITE DIRECT Structure of synovial tissue of joint body structure NOTE USING ACCESS DEVICE replaces the attribute ACCESS INSTRUMENT which has been retired for the January 2007 release When USING ACCESS DEVICE has a value of Endoscope device physical object or one of its descendents it no longer requires the use of ACCESS Endoscopic approach access qualifier value as was previously required for Endoscopic procedures 5 ACCESS This attribute describes the route used to access the site of a procedure It is used to distinguish open closed and percutaneous procedures Permissible values include the following concept and its descendants e Surgical access values qualifier value 309795001 Example Open reduction of fracture procedure ACCESS Open approach access qualifier value NOTE As of the January 2007 release ACCESS is no longer used to capture that the route used to access a procedure was endoscopic The information that was previously captured by ACCESS Endoscopic approach access qualifier value is adequately captured with USING ACCESS DEVICE Endoscope device physical object 6 APPROACH This attribute specifies the directional relational or spatial access to the site of a procedure Permissible values include the following concept and its descendants e Procedural approach qualifier value 103379005 SNOMED
89. tribute is frequently used in conjunction with FINDING METHOD Permissible values include the following concepts and their descendants e Subject of record or other provider of history person 419358007 e Subject of record person 410604004 e Provider of history other than subject person 420058008 e Performer of method person 420158005 Examples 1 On examination ankle clonus finding FINDING INFORMER Performer of method person 2 Complaining of a headache finding FINDING INFORMER Subject of record or other provider of history person SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Attributes Page 4 10 4 3 Attributes used to define Procedure concepts NOTE Permissible values for these attributes include the concepts listed and their descendanis Table 4 2 Approved Procedure attributes summary table Defining Attribute Permissible Values Concepts listed and their descendents PROCEDURE SITE PROCEDURE SITE DIRECT PROCEDURE SITE INDIRECT Anatomical structure body structure Acquired body structure 280115004 91723000 PROCEDURE MORPHOLOGY DIRECT MORPHOLOGY INDIRECT MORPHOLOGY Morphologically abnormal structure 49755003 METHOD Action 129264002 PROCEDURE DEVICE DIRECT DEVICE INDIRECT DEVICE Device 49062001 USING DEVICE USING ACCESS DEVICE ACCESS Surgical access values 309795001 APPROACH Proce
90. tributes used to define Event concepts NOTE Permissible values for these attributes include the concepts listed and their descendants Table 4 5 Attributes for Event concepts summary table Defining Attribute Permissible Values Concepts listed and their descendants ASSOCIATED WITH Clinical Finding 404684003 Procedure 71388002 Event 272379006 Organism 410607006 Substance 105590001 Physical object 260787004 Physical force 78621006 Pharmaceutical biologic product 373873005 SNOMED CT Concept 138875005 For this concept only the concept and not all of its descendents is allowed as a value CAUSATIVE AGENT Organism 410607006 Substance 105590001 Physical object 260787004 SNOMED CT Concept 138875005 Physical force 78621006 Pharmaceutical biologic product 373873005 For this concept only the concept and not all of its descendents is allowed as a value DUE TO Clinical Finding 404684003 Event 272379006 AFTER Clinical Finding 404684003 Procedure 71388002 OCCURRENCE Periods of life 282032007 In January 2006 a limited number of concepts from the Clinical finding hierarchy were moved to the Event hierarchy The attributes used to define those concepts when they were descendents of Clinical finding were retained after the concepts were moved to the Event hierarchy Definitive editorial policies for the use of attributes in the Event hierarchy have yet to be established SNOM
91. ual Sixth Edition 2002 published by Springer Verlag New York www springer ny com Used with permission of the American Joint Committee on Cancer AJCC Chicago Illinois e The Anesthesia Patient Safety Foundation s APSF Data Dictionary Task Force Some material contributed Copyright 2003 APSF Inc Used by permission of the APSF e This work contains terms from the British Association of Dermatology BAD and is used by permission of BAD Crown Copyright 2003 British Association of Dermatologists e This work contains terms from The Royal College of Anaesthetists RCoA and is used by permission of RCoA Crown Copyright 2003 The Royal College of Anaesthetists e This work contains terms from the Authorized Osteopathic Thesaurus and is used by permission of the American Association of Colleges of Osteopathic Medicine and the American Osteopathic Association SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists
92. ual Medicinal Product VMP The most granular level is the Virtual Medicinal Product VMP The VMP is a representation at the level of generality that would appear on a physician s prescription The product name strength and dose form are all represented in the Fully Specified Name This level can be used to support providers with drug ordering in CPOE and e prescribing use cases Example Diazepam 5mg tablet product Name Strength Dose form Virtual Therapeutic Moiety VTM The Virtual Therapeutic Moiety VTM level represents a more general level of granularity than the VMP level VTMs include the product name but not formulation dose or strength in the Fully Specified Name The HAS ACTIVE INGREDIENT attribute which relates the product to the Substance it contains can be assigned to this level or to any of the subtypes of this level Example Diazepam product All Virtual Medicinal Products VMP have a direct link to the Virtual Therapeutic Moiety VTM via an IS_A relationship Example Diazepam product This is a VTM IS A Oral form diazepam product IS A Diazepam 5mg tablet product VMP There are additional levels in the Pharmaceutical biologic product hierarchy that provide structure and organization For example some subtypes of VTM contain only Dose form information and not Strength SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 6
93. uiding Principles Development Process and Acknowledgements C 1 SNOMED CT A comprehensive terminology for health care In 1999 the College of American Pathologists CAP and the U K formed a strategic alliance to create a convergence of SNOMED Reference Terminology SNOMED RT and Clinical Terms Version 3 CTV3 The resulting work SNOMED Clinical Terms SNOMED CT combines the robust strength of SNOMED RT in the basic sciences and laboratory and specialty medicine with the primary care content of CTV3 formerly known as the Read Codes SNOMED CT is a comprehensive clinical reference terminology that provides clinical content and expressivity for clinical documentation and reporting The terminology enables clinicians researchers and patients to share comparable data SNOMED CT was founded on four basic principles that have guided development activities related to the distribution table structure and clinical content e Development efforts encompass broad inclusive involvement of diverse clinical groups and medical informatics experts e Clinical content is quality focused and adheres to editorial policies e A quality improvement process open to public scrutiny and vendor input to ensure that the terminology is useful within healthcare applications e There should be minimal barriers to adoption and use The design has been driven by the expressed needs of software developers for features that improve their ability to develop
94. useful applications SNOMED CT provides a standardized clinical terminology that is essential for effective collection of clinical data its retrieval aggregation and re use as well as interoperability C 2 SNOMED CT quality development process The SNOMED CT development process incorporates the efforts of internal and external modelers Content is edited by clinical editors who follow formal modeling guidelines The integration of SNOMED RT and Clinical Terms Version 3 to create the first release was a three year process that involved several stages of review and quality assurance e Description mapping NHS editors evaluated each SNOMED concept and term and mapped it to the Clinical Terms Version 3 terminology SNOMED editors performed the same task mapping primarily disorders and procedures from Clinical Terms Version 3 to SNOMED RT e Description mapping conflict resolution Mapping discrepancies that occurred between NHS and SNOMED editors underwent a conflict resolution process to definitively place each concept within the merged hierarchy e Autoclassification The merged database following description mapping conflict resolution underwent a series of quality control checks including autoclassification to identify and eliminate cycle errors e g Concept A IS_A B and Concept B IS_A A and equivalency errors where two defined concepts have the exact same definition e Ongoing refinement The quality control process is
95. usually be applied to one hierarchy and for a few attributes to more than one hierarchy The hierarchy or hierarchies to which an attribute can be applied are referred to as the domain of the attribute Each attribute can be given a limited set of values this set of values is called the range of the attribute Domain The Domain is the hierarchy to which a specific attribute can be applied The Domain of the attribute ASSOCIATED MORPHOLOGY is the Clinical finding hierarchy A Procedure cannot have an ASSOCIATED MORPHOLOGY A Procedure has a PROCEDURE MORPHOLOGY Range The Range is the set of values allowed for each attribute For example the Range for ASSOCIATED MORPHOLOGY is Morphologically abnormal structure morphologic abnormality and its descendents and the range for FINDING SITE is Anatomical structure body structure or Acquired body structure body structure in the Body structure hierarchy FINDING SITE ConceptID1 ee ConceptID2 q Lung structure 5 Defining attribute nnn nn nenm y FINDING SITE Lung structure Figure 4 1 Example Pneumonia FINDING SITE Lung structure The domain for the FINDING SITE attribute is the Clinical finding hierarchy In this example Figure 4 1 the attribute FINDING SITE has the value Lung structure body structure Lung structure body structure is found in the Anatomical structure body structure subhierarchy which is in the allowed range f
96. utes relationship types can be used to logically define a concept defining attributes This sub hierarchy also includes non defining attributes like those used to track historical relationships between concepts or attributes that may be useful to model concept definitions but which have not yet been used in modeling pre coordinated concepts in SNOMED CT Examples of Defining attributes e S_A attribute e Concept model attribute attribute Laterality attribute Procedure site attribute Finding site attribute Associated morphology attribute SNOMED CT User Guide January 2007 Release 2002 2007 College of American Pathologists Hierarchies Page 5 11 Examples of Non defining attributes e Concept history attribute attribute Replaced by attribute Was a attribute e Unapproved attribute attribute Relieved by attribute Has assessment attribute Qualifier value The Qualifier value hierarchy contains some of the concepts used as values for SNOMED CT attributes that are not contained elsewhere in SNOMED CT However the values for attributes are not limited to this hierarchy and are also found in hierarchies other than Qualifier value For example the value for the attribute LATERALITY in the concept shown below is taken from the Qualifier value hierarchy e Left kidney structure body structure LATERALITY Left qualifier value However the value for the attribute FINDING SIT

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