1.
Which of the following statements is true about SNOMED CT
Correct Answer(s)
B. It uses unique identifiers to represent clinical ideas
C. Its design is based on a peer reviewed paper outlining requirements for clinical terminologies in the twenty-first century
Explanation
SNOMED CT use unique integer identifiers to represent clinical ideas and was designed taking account of Jim Cimino's paper "Desiderata for Controlled Terminologies in the Twenty-First Century" published in 1998. It is a polyhierarchy, which means a concept can have more than one parent in the hierarchy - this means it is not a statistical classification. It is designed to improve clinical records that assist the delivery of care and to minimize errors and advance clinical knowledge. It is not focused directly on billing but it can be mapped to statistical classifications and to billing codes where these are required.
2.
Which of the following are characteristics of the main SNOMED CT hierarchy
Correct Answer(s)
B. It is a polyhierarchy
C. It represents a hierarchy of subtypes
E. It is a directed acyclic grapH (DAG)
Explanation
The SNOMED CT hierarchy is a polyhierarchy because concepts in the hierarchy can have multiple parents. The hierarchy is based on subtype "is a" relationships. The end result of the building the hierarchy is Directed Acyclic Graph (DAG). Directed because the relationship is not reverseable (if "A is a B" then it is not possible that "B is a A") and acyclic because cyclical subtype relationships would clearly be illogical (is "A is a B" and "B is a C" it is not possible that "C is a A"). Strictly speaking the hierarchy is not multi-axial hierarchy because it has a single root concept ("SNOMED CT Concept") and all other concepts are a subtype of this concept. However, rather misleadingly the top-level hierarchies are sometimes referred to axes. The SNOMED CT hierarchy is represented by relationships - not by a sequence of characters.
Historical Note: Before 2001 now-obsolete versions of SNOMED (including SNOMED 3) were multi-axial, the axes of SNOMED 3 were defined by the initial character of the code and codes from different axes needed to be combined to represent a concept. In 2002 with the release of SNOMED CT this approach changed.
3.
Which of the following types of concepts are included in SNOMED CT
Correct Answer(s)
A. Clinical findings
B. Procedures
C. Substances
E. Organisms
Explanation
SNOMED CT has a very broad scope of coverage because it includes not only clinical concepts but also other types of concept used to define clinical concepts. It does include geographical regions but it does not include astronomical bodies such as planets.
4.
SNOMED CT enables meaning-based retrieval of clinical information
Correct Answer
A. True
Explanation
Meaning-based retrieval is a key benefit of SNOMED CT. See www.ihtsdo.org/benefits.pdf
5.
Which of the following are SNOMED CT components
Correct Answer(s)
B. Relationships
C. Concepts
E. Descriptions
Explanation
The three components of SNOMED CT are "concepts" each of which represents a clinical meaning, "descriptions" which associate human-readable term or phrase with a "concept" and "relationships" which link concept to one another based on the semantic relationships between them.
6.
Which of the following statements about "preferred terms" is true
Correct Answer
B. A preferred term is a synonym that is preferred for use in a particular language or dialect
Explanation
A preferred term is a synonym marked as "preferred" in the reference set for a language or dialect. There can be many different preferred terms - one for each language or dialect. In some cases a preferred term in one dialect may be an acceptable synonymous term in another dialect.
7.
SNOMED CT release files are tab-delimited ASCII text files
Correct Answer
B. False
Explanation
SNOMED CT release files are tab-delimited UTF-8 encoded text files. The standard latin alphabet, numbers and common grammatical symbol have the same values in UTF-8 and ASCII. However, UTF-8 supports the full Unicode character set by permitting multibyte encoding of characters where necessary.
8.
Which of the statements below are true for the following SNOMED CT expression
71620000 | fracture of femur | :
272741003 | laterality | = 7771000 | left |
, 363698007 | finding site | = 41111004 | bone structure of shaft of femur |
, 116676008 | associated morphology | = 52329006 | fracture, open |
Correct Answer(s)
B. It is a valid close-to-user SNOMED CT expression
D. It is a valid representation of an open fracture of the shaft of the left femur
E. It means the same as: 71620000:272741003=7771000,363698007=41111004,116676008=52329006
Explanation
This is valid close to user expression and it represents "open fracture of the shaft of the left femur". It is not a normal form expression because in the normal form laterality is nested under the body structure to which it applies (in this case it would be nested under "shaft of femur"). The expression representation without terms is also valid because the expression grammar allows terms to be optionally added to assist human-readability.
9.
Maps from SNOMED CT to ICD-10 distributed by the IHTSDO
Correct Answer(s)
B. Include rules that help to determine appropriate maps for a concept depending on other clinical or demograpHic information
C. Are used as a foundation for maps to ICD-10-CM developed by the US National Library of Medicine
D. Are represented using Reference sets.
Explanation
SNOMED CT maps are represented as Reference sets. The ICD-10 map in the international release includes rules that help determine maps when a clinical concept represented in SNOMED CT has several possible maps to ICD-10 categories that depending on co-existing conditions, age and sex of the patient or other factors. The maps to ICD-10 are used as basis for further mapping work to link to ICD-10-CM categories and these maps are developed in the US by NLM.
10.
Which of the following statements are true about IHTSDO Members?
Correct Answer(s)
A. They have a seat on the IHTSDO General Assembly
B. They pay an annual membership fee that depends on wealth of their country
E. They are permitted to produce, maintain and distribute translations of SNOMED CT
Explanation
IHTSDO Membership is open to all countries and the fees payable for membership are based on the relative wealth of the country according World Bank GNI metrics. One representative of each Member country sits on the IHTSDO General Assembly. IHTSDO Members are permitted (but not required) to create National SNOMED CT Extensions and they are permitted to translate SNOMED CT concept into their national language(s) or dialects. Members are not responsible for collecting fees for use in their country because there are no fees for use of SNOMED CT in Member countries.
11.
The SNOMED CT Affiliate License Agreement ...
Correct Answer(s)
B. Is issued by the IHTSDO and permits use of the SNOMED CT International Release
D. Permits use of SNOMED CT in non-Member Territories subject to payment of a fee per institution
Explanation
The Affiliate License Agreement issued by the IHTSDO and permit use of the SNOMED CT International Release. Some IHTSDO Members act as licensing agents for the IHTSDO but the license is still issued by IHTSDO as the licensor. IHTSDO Members are permitted to license their own National Extensions to IHTSDO Affiliates. Affiliates are required to report use in non-Member Territories and to pay fees for those uses. Affiliates are not permitted to translate SNOMED CT content. IHTSDO Members are permitted to translate SNOMED CT into their national language(s) and dialect(s).
12.
The SNOMED CT International Release is updated ...
Correct Answer
D. Every six months
Explanation
Since January 2002, SNOMED CT International Edition has been released regularly every six months (31 January and 31 July each year). The schedule will continue until further notice. Some National Extensions of SNOMED CT are updated more frequently. At some point more frequent releases of the International Edition may also be considered.
13.
A SNOMED CT Extension can only be created, maintained and distributed by ...
Correct Answer
D. An IHTSDO Member or Affiliate that has been allocated a namespace identifier
Explanation
Members or Affiliate Licensees can create SNOMED CT Extensions. However, in order to do this they must request, receive and use a namespace identifier. The namespace identifier distinguishes the content of Extensions created by different originators and ensures that the same SNOMED CT cannot be legitimately issued by more than one organization.
14.
How can you tell if a particular concept identifier represents a procedure
Correct Answer(s)
A. It has a fully specified name containing the tag "(procedure)"
C. It is linked by a chain of one or more "is a" relationships to the concept "procedure"
D. It is a descendant of the concept "procedure" in the subtype hierarchy
Explanation
All procedures are subtype descendants of the concept "procedure" (i.e. every procedure is defined as being a type of procedure). The subtype relationships in SNOMED CT are called "is a" relationships and by traversing a chain of "is a" relationships from a procedure concept eventually the "procedure" concept will be reached. Based on an editing convention, the fully specified name for a procedure concept will end with the work "procedure" in brackets. While the bracketed "hierarchy tag" a useful human-readable indication, it is not recommended as a good general way to determine whether one concept is subtype of another.
15.
Which of the following are the names of current SNOMED CT release file structures?
Correct Answer(s)
A. Reference set
B. Concept
D. Description
E. Relationship
Explanation
Subsets were a release file in the old release format (RF1) this was replaced in early 2012 by Release Format 2 (RF2) which includes a more flexible mechanism call "Reference sets" which can be used to represent a wide range of different types of additional information, including subsets.
16.
The relationships in the SNOMED CT "Relationship" release file" :
Correct Answer(s)
D. Represent the set of non-redundant relationships inferred from relationships authored by SNOMED CT editors
E. Are generated by applying description logic to relationships stated by SNOMED CT editors
Explanation
The "Relationship" release file contains non-redundant relationships inferred from the relationships authored by the SNOMED CT editors. The inferred view is generated by using a description logic classifier which ensure the consistency of defining relationships. Additional relationships are inferred by the classifier are included in the "Relationship" file. Some relationships that are authored turn out to be redundant after classification and are not included in the "Relationship" file.
17.
The relationships in the SNOMED CT "stated relationships release file"
Correct Answer(s)
A. Contain all the relationships authored by SNOMED CT editors which have passed quality assurance review
E. Have all been authored by SNOMED CT editors
Explanation
The "Stated Relationship" release file contains all the relationships that have been authored and passed quality assurance review. It does not include any inferred relationships.
18.
Which of the following associations is a defining relationship of "appendectomy"
Correct Answer(s)
A. | method | = | excision - action |
D. | procedure site - Direct | = | appendix structure |
Explanation
Appendectomy is defined as the excision of the appendix. While a laparoscope may be used it is not a defining attribute of appendectomy (it is a defining attribute of Laparoscopic appendectomy). Although appendectomy is a treatment for appendicitis this is not a defining attribute - it is possible to remove the appendix even when the patient does not have appendicitis.
19.
Which of the following associations are defining relationships of "family history of diabetes mellitus type 1"?
Correct Answer(s)
B. | subject relationship context | = | person in family of subject |
C. | associated finding | = | diabetes mellitus type 1 |
D. | is a | = | family history of disorder |
Explanation
Family history of a disorder is not type of that disorder. It is a type of family history of disorder. The link between family history and the disorder is referred to as | associated finding | and the | subject relationship context | indicates that the person who has (or had) the disorder is a family member.
20.
Which of these expressions are equivalent to "Cholecystectomy and exploration of bile duct"?
Correct Answer(s)
A. | cholecystectomy | + | exploration of bile duct |
C. | procedure | : { | method | = | excision - action | , | procedure site - Direct | = | gallbladder structure | }, { | method | = | exploration - action | , | procedure site - Direct | = | bile duct structure | }
D. | cholecystectomy | : { | method | = | exploration - action | , | procedure site - Direct | = | bile duct structure | }
Explanation
The correct option all resolve to the same normal form in which excision of gall bladder and exploration of bile duct are represented by separate relationship groups. The incorrect options fail to unambiguously associate excision with the gall bladder while separately associating exploration with the bile duct.
21.
Which statements are true of a SNOMED CT RF2 "FULL" release concept files for the International Release?
Correct Answer(s)
B. The data contains full history back to the first SNOMED CT release in January 2002
C. All the rows in the January 2013 are present and unchanged in the July 2013 release
E. All concepts released on or before the release date are represented in the file.
Explanation
The data in a FULL release goes back to the very first release of SNOMED CT in January 2002 and shows all changes since that date. Rows once added to the a release remain unchanged in all subsequent FULL releases of that file and changes are made by adding the revised version of a component as a new row with a more recent effectiveTime.
22.
Which statements are true of a SNOMED CT RF2 "SNAPSHOT" release concept file for the International Release?
Correct Answer(s)
B. All the rows in this file are also present (with an identical date) in the "FULL" release for the same release date
E. There is only one representation of each concept in the file
Explanation
A SNAPSHOT release contains the most recent row for each component at the time of the release. The SNAPSHOT is generated by filtering the FULL release so that where there may be several rows with the same id in the FULL release, the SNAPSHOT only includes one row for each distinct id (i.e. the row highest effectiveTime). Therefore, every row in the SNAPSHOP is identical to a row in the FULL release. In the case of inactive concepts, the most recent row is a row representing the fact that the concept is inactive - so these inactive concept are represented in the SNAPSHOT.
23.
Which statements are true of a SNOMED CT RF2 "DELTA" release concept file for the International Release?
Correct Answer(s)
A. All the data in the file has an effectiveTime that is after the date of the previous release and less than or equal to the current release date
B. All the rows in this file are also present (with an identical date) in the "FULL" release for the same release date
C. All the rows in this file are also present (with an identical date) in the "SNAPSHOT" release for the same release date
Explanation
The DELTA release only includes rows that have been added or changed since the last release. Therefore, the rows in the DELTA release include all rows in the FULL release for the same date that have an effectiveTime greater than the date of the previous release. The changes since the last release represent the most recent status of the concept so the rows in the DELTA release will also appear in the SNAPSHOT release. Where a concept has been made inactive since the last release these inactive rows will be in the DELTA release.
24.
An RF2 SNAPSHOT view for the most recent release date can be generated from ...
Correct Answer(s)
A. A FULL release for the most recent release date
D. A SNAPSHOT release for the previous release date and a DELTA release for the most recent release date
Explanation
The SNAPSHOT view of a SNOMED CT release can be generated from a FULL release - by taking only the row with the highest effectiveTime for each distinct id. The SNAPSHOT view of a SNOMED CT release can also be generated from the previous SNAPSHOT and the most recent DELTA release. In this case the two files are merged. Rows in the DELTA file are added to the new SNAPSHOT view if the id is unique, where a DELTA release row has the same id as a previous SNAPSHOT row, the row from the DELTA release replaces the row in the previous SNAPSHOT.
25.
Which of the following statements are true about SNOMED CT identifiers (SCTID)?
Correct Answer(s)
B. An SCTID tells you nothing about the meaning of a concept or its relationships to other concepts
C. Every SCTID contains a check-digit
D. Every SCTID includes a partition identifier which indicates whether the SCTID identifies a concept, description or relationship
Explanation
An SCTID is a number (a 64 bit integer) and the number itself says nothing about the meaning of the component that it identifies (the meaning of a concept is represented by relationships between concepts). The SCTID does contain some additional information: (a) a partitionId which indicates which type of component it represents (concept, description or relationship) and whether the component was originated in an Extension, (b) a check-digit and (c) in the case of components that are part of an Extensions a namespace identifier which indicates which Extension it was originated in. The namespace identifier is not present in components that originated in the SNOMED CT International Release.
26.
Benefits of using SNOMED CT to assist decision support in Electronic Health Record (EHR) systems include:
Correct Answer(s)
A. Reduction of risk of costly treatment errors by more comprehensive retrieval of clinical information
B. More consistent representation of clinical information collected in different specialties
E. Ability to recognize alternative representations of similar meanings
Explanation
The broad coverage of SNOMED CT enables more consistency of clinical recording across different clinical specialties. The SNOMED CT concept model uses Description Logic to enable alternative representations of similar meanings to be recognized and this enables effective meaning based retrieval of processable clinical information. SNOMED CT does not itself include decision support or interaction checking but meaning-based retrieval from records that use SNOMED CT enables decision support tools to reduce costly errors in treatment and unnecessary duplication of investigations.
27.
A user needs to record a procedure which is not currently in SNOMED CT. Which of the following approaches should be considered to enable this information to be recorded?
Correct Answer(s)
A. Advise the user to record a more general (supertype) concept and enter the procedure name as free text
B. Create a concept in a local SNOMED CT Extension to represent the required procedure
C. Request addition of the required procedure to a National Extensions of SNOMED CT
D. Submit a request to the online SNOMED CT International Request Submissions system
Explanation
The meaning of a SNOMED CT concept should never be changed to meet a local requirement (concept permanence is key feature of SNOMED CT). Use of a postcoordinated expression is a useful way to represent more detailed meanings. However, if this is not supportable or does not provide sufficient specificity other approaches can be followed: It is reasonable to use a more general concept and add qualifying text where the required more specific meaning is not frequently required or as a stopgap while pursuing other approaches. If the organization maintains its own Extension then the concept can be added locally. However, if the same requirement is likely to be shared nationally or internationally then a request for addition should be raised with the National Member or IHTSDO.
28.
Which of the following features are part of the design of SNOMED CT?
Correct Answer(s)
A. Formal definitions of concepts
B. Component permanence
D. Polyhierarchy
E. Graceful evolution
Explanation
SNOMED CT does not have semantic identifiers instead it uses relationships between concepts to represent formal definitions of concepts. These formal definitions are used to compute a subtype hierarchy - a polyhierarchy in which a concept may have more than one parent supertypes. Concepts (and other SNOMED CT components) are permanent and identifiers are never reused for a different purpose. However, SNOMED CT is able to evolve gracefully using a formal approach to changes and additions, all of which are version tracked.
29.
In which of the following SNOMED CT hierarchies would you find a concept representing "Diabetes mellitus type 2"
Correct Answer(s)
C. Disorders
E. Findings
Explanation
"Diabetes mellitus type 2" is a disease and thus appears as a subtype in the "Disorder" hierarchy. However, is a type of "Diabetes mellitus type 2" is also a subtype of "Clinical finding" because "Disorders" are types of "Clinical findings".
30.
Which of the following are recognized as distinct description types in SNOMED CT Release Format 2?
Correct Answer(s)
A. Synonyms
B. Fully specified name
D. Definition
Explanation
In both RF1 and RF2 "Fully specified name" and "Synonym" are description types. However, in RF2 the preferred term is description of type "Synonym" which is marked as "Preferred". Also in RF2, the text definitions of some concept are included in an additional Descriptions file and they have the description type "Definition".
31.
One of the attributes used to define Clinical Finding concepts is called | clinical course |. What is this attribute used to represent?
Correct Answer
A. Both the onset and course of a disease
Explanation
The | clinical course | attribute is used to represent both the onset and course of a disease.
32.
A precoordinated SNOMED CT expression ...
Correct Answer(s)
A. Contains a single identifier referring to one concept
B. Represents the same meaning as a single SNOMED CT concept
D. May be interpreted differently depending on surrounding contextual information
Explanation
The definition of a precoordinated expression is an expression containing only one concept identifier. The meaning of a precoordinated expression matches the meaning of the concept to which it refers. Surrounding information in a record may add contextual information that refines or modifies the interpretation of an expression (e.g. a procedure has a different interpretation if it appears in record sections such as "surgical history", "plan" or "operation notes"). The inclusion of terms in a SNOMED CT expression is optional.
33.
A postcoordinated SNOMED CT expression ...
Correct Answer(s)
A. May include contextual information
B. Contains two or more concept identifiers
D. May have the same meaning as a single SNOMED CT concept
Explanation
The definition of a postcoordinated expression is an expression containing more than one concept identifier. Some of the concept identifiers may contribute contextual information such as indicating that a disorder is past history or family history rather than applying to the subject of the record at the present time. It is possible for a postcoordinated expression to represent the same meaning as an existing concept - although many postcoordinated expressions will not be matched by single concepts. The inclusion of terms in a SNOMED CT expression is optional.
34.
The IHTSDO ...
Correct Answer(s)
A. Owns and maintains SNOMED Clinical Terms
D. Is a not for profit association governed by its National Members
Explanation
IHTSDO (International Health Terminology Standards Development Organization) owns, maintains, licenses and distributes SNOMED Clinical Terms (SNOMED CT). It is a not-for-profit association governed by all its National Members through the General Assembly.
35.
SNOMED CT subtype relationships ...
Correct Answer(s)
A. Have the relationship type | is a |
D. Directly relate every clinical concept to one or more less specific parent concepts
Explanation
Subtype relationships have a relationship type that is represented by the concept | is a |. They directly relate concepts to one or more less specific concepts and these direct supertypes are referred to as parents of the concept. Subtype relationships indirectly relate clinical concepts to broad clinical categories such as "clinical finding", "procedure" and "observable entity".