Transformation Level 1
Terminology servers at Level 1 will accept any expressions represented in valid classifiable form, as in Level 0. Additionally, some expressions that are not already in classifiable form will also be accepted. These will mainly be syntactically compliant expressions that are not MRCM compliant, but which the server can unambiguously transform to derived expressions that are MRCM compliant, using predefined automated transforms.
Loose Attributes
A loose attribute is any attribute within a CTU expression that is not in an attribute group AND the MRCM specifies:
that it should be grouped, or
that it is in the wrong domain
Scope of Transformations
Level 1 transformations of CTU expressions may apply to expressions meeting the following criteria.
Transformations can only apply where there is no definition status
There must be only one focus concept
Level 1 transformations can only apply to loose attributes (as defined above)
When the expression contains a mixture of loose attributes and attribute groups, the attribute groups are effectively treated as for Level 1, so no transformation of these are attempted
Transformation Process
Expression syntax, concepts being active and MRCM attribute-range validation should be applied before the transformation step. Implementations should fail fast if these are not met and not attempt transformation. This simplifies the preconditions for specific transformations.
The process of applying the transformations is iterative. This includes: collecting the set of remaining loose attributes, then applying the next transformation, and repeating until each transformation has been applied once. When each specific transformation is applied it should be greedy and transform all the loose attributes that meet the conditions of that transformation.
The list of transformations must be applied in a specific order; to ensure that the same classifiable expression is reached every time by all implementations.
Transformations
The allowed patterns can be summarized as follows:
Refining Existing Attribute
Adding a Self-grouped Attribute
Adding Severity to Clinical Findings
Lateralizing Clinical Findings
Lateralizing Procedures
Adding Context to Clinical Findings
Adding Context to Procedures
The following sections elaborate on the preconditions and behaviour of each pattern.
Refining Existing Attribute
In this case, the terminology server will accept attributes-value pairs with the following characteristics:
The attribute is already present in the NNF of the focus concept
The attribute value stated in the expression is a subtype of the attribute value of the focus concept
Important Notes
If no groups are stated in the CTU expression (i.e. attributes are declared as loose attributes), the terminology server will accept attribute-value pairs correctly belonging to role groups of the focus concept as follows:
The terminology server will accept attribute-value pairs that refine one or more of the attribute-value pairs of the focus concept, i.e.
The attribute type should be the same as, or a subtype of, an attribute that already exists in the NNF of the focus concept, for which
The attribute value may be the same as, or a subtype of, the existing attribute value
The terminology server will reject attribute-values, if this is a supertype of the attribute value used in the definition of the focus concept
If groups are stated in the CTU expression
The terminology server will accept groups that refine an existing role group of the concept, i.e. the group stated in the CTU should represent a subtype of the role group of the focus concept
The following table provides examples of CTU expressions candidate to this pattern, and their evaluation at level 1.
Accept
=== 29477005 |Repair of fracture with sequestrectomy| : { 260686004 |Method| = 129284003 |Surgical action| , 363704007 |Procedure site| = 272673000 |Bone structure| , 405816004 |Procedure morphology| = 72704001 |Fracture| } { 260686004 |Method| = 257903006 |Repair - action| , 405813007 |Procedure site - Direct| = 26107004 |Structure of musculoskeletal system| } { 260686004 |Method| = 129304002 |Excision - action| , 405813007 |Procedure site - Direct| = 272673000 |Bone structure| , 363700003 |Direct morphology| = 4857006 |Sequestrum| } { 260686004 |Method| = 129284003 |Surgical action| , 363704007 |Procedure site| = 41111004 |Bone structure of shaft of femur| , 405816004 |Procedure morphology| = 72704001 |Fracture| } { 260686004 |Method| = 257903006 |Repair - action| , 405813007 |Procedure site - Direct| = 41111004 |Bone structure of shaft of femur| } { 260686004 |Method| = 129304002 |Excision - action| , 405813007 |Procedure site - Direct| = 41111004 |Bone structure of shaft of femur| , 363700003 |Direct morphology| = 4857006 |Sequestrum| }
Accept
=== 118473000 |Treatment of complex fracture| : { 260686004 |Method| = 257903006 |Repair - action| , 405813007 |Procedure site - Direct| = 272673000 |Bone structure| } { 260686004 |Method| = 129284003 |Surgical action| , 363704007 |Procedure site| = 272673000 |Bone structure| , 405816004 |Procedure morphology| = 72704001 |Fracture| } { 260686004 |Method| = 410814006 |Surgical reduction - action| , 363704007 |Procedure site| = 272673000 |Bone structure| , 405816004 |Procedure morphology| = 72704001 |Fracture| }
Accept
=== 281444001 |Loosening of total shoulder replacement| : { 363698007 |Finding site| = 85537004 |Glenohumeral joint structure| } { 255234002 |After| = 31884000 |Implantation of joint prosthesis into shoulder joint| } { 47429007 |Associated with| = 304125002 |Total shoulder replacement prosthesis| } { 255234002 |After| = 733429004 |Prosthetic total arthroplasty of right shoulder| }
Accept
Reject
N/A
Accept
=== 6471000179103 |Transplantation of kidney and pancreas| : { 260686004 |Method| = 410820007 |Surgical transplantation - action| , 405813007 |Procedure site - Direct| = 64033007 |Kidney structure| , 363701004 |Direct substance| = 420852008 |Kidney graft - material| } { 260686004 |Method| = 410820007 |Surgical transplantation - action| , 405813007 |Procedure site - Direct| = 15776009 |Pancreatic structure (body| , 363701004 |Direct substance| = 421263007 |Pancreas graft - material| } { 260686004 |Method| = 410820007 |Surgical transplantation - action| , 405813007 |Procedure site - Direct| = 9846003 |Right kidney structure| , 363701004 |Direct substance| = 420852008 |Kidney graft - material| }
Adding a Self-grouped Attribute
Transformation Preconditions
This transformation will be applied to all loose attributes that meet the following conditions:
The attribute applies to the MRCM domain of the focus concept (see table below)
Only one instance of the attribute is stated in the CTU expression
Although the MRCM allows multiple instances, this transformation condition aims to avoid misinterpretation of the intended meaning
Either:
The attribute type is not already used in the necessary normal form of the focus concept
For example, if the focus concept already has a |Due to| attribute in the NNF then an expression including |Due to| would not be accepted
The attribute type is already used in the necessary normal form of the focus concept and the value is equal to or a subtype of the existing value
I.e. it represents a refinement
The following table shows the self-grouped attributes and the domain they apply to
before
priority
during
has focus
after
due to
clinical course
temporally related to
associated with
Please refer to the Editorial Guide for instructions on the use and the implied meaning of these attributes:
Clinical Finding Defining Attributes
Procedure Defining Attributes
As part of the expression transformation process, the terminology server will place the attributes in groups on their own, as shown in the examples below.
Examples of CTU expressions candidate to this pattern, and their evaluation at level 1.
Accept
Adding Severity to Clinical Findings
At level 1, the terminology server will accept CTU expressions matching the following pattern:
This means that CTU expressions that includes the severity attribute will be accepted if the following criteria are met:
The focus concept is a subtype of |Clinical finding| (but not a subtype of 162465004 | Symptom severity (finding)| )
The attribute value must be a subtype of 272141005 | Severities (qualifier value)|
When applied as a loose attribute, only one instance of the attribute may be stated in the CTU expression
The severity attribute is not already present in the definition of the focus concept
As part of the transformation process, the terminology server will place the attribute in a group on its own, similar to the self-grouped attributes.
Important Notes: Please be aware that caution should be taken when adding |severity| to a focus concept, because severities are difficult to generalize and may be subject to individual interpretation, as stated in the Editorial Guide.
Examples of CTU expressions candidates to this pattern, and their evaluation at level 1.
Accept
Lateralizing Clinical Findings
The terminology server will accept CTU expressions matching the following pattern:
The transformation of expressions following this pattern will include the following steps:
Copy the defining properties and role groups of the focus concept (as present in the NNF) to the classifiable form expression
Replace the value of the |Finding site| attribute with a nested expression:
From:
To:
Important Notes
The terminology server will only accept expressions complying to this pattern if the focus concept of the CTU expression has the following characteristics:
The focus concept
includes only one role group with a |Finding site| attribute OR
includes two or more role groups with a |Finding site| attribute WHERE
the value of the finding site attribute in each role group is the same concept
includes no attributes with values that are already lateralized anatomical structures (ie values whose own definitions already include a value for the 272741003|Laterality| attribute
The value of the finding site attribute is a member of the 723264001 | Lateralizable body structure reference set|
being a member of this refset means that the associated body structure is lateralizable, and does not already state a laterality other than 182353008 |Side|
Transformation of bilateral findings
When applying the concept 51440002 | Right and left| as the value for the 272741003 | Laterality| attribute, the transformation should be done in accordance with the modeling applied to the content in the International Edition of SNOMED CT.
This means that the transformation steps described above should be applied twice; one for each lateral half, as illustrated in the example below.
Examples
Accept
Reject
Accept
=== 449702005 |Cellulitis and abscess of lower limb| : { 363698007 |Finding site| = ( 61685007 |Lower limb structure| : 272741003 |Laterality| = 7771000 |Left| ), 116676008 |Associated morphology| = 385627004 |Cellulitis| } { 363698007 |Finding site| = ( 61685007 |Lower limb structure| : 272741003 |Laterality| = 7771000 |Left| ), 116676008 |Associated morphology| = 44132006 |Abscess| }
Lateralizing Procedures
The terminology server will accept CTU expressions matching the following pattern:
The transformation of expressions following this pattern will include the following steps:
Copy the defining properties and role groups of the focus concept (as present in the NNF) to the classifiable form expression
Replace the value of the |Procedure site| attribute (or any of its subtypes / @siteAttribute) with a nested expression:
From:
To:
Important Notes
The terminology server will only accept expressions complying to this pattern where the focus concept has the following characteristics:
The focus concept
includes only one role group with a @siteAttribute 363704007 |Procedure site| attribute (or any subtype of 363704007 |Procedure site|) OR
includes two or more role groups with a 363704007 |Procedure site| attribute (<< 363704007 |Procedure site|) WHERE
the @bodySite value is the same for all procedure site attributes
includes no attributes with values that are lateralized anatomical structures
The value of the procedure site attribute is a member of the 723264001 | Lateralizable body structure reference set|
i.e. the associated body structure is lateralizable, and
the associated body structure does not already state a laterality
Transformation of bilateral procedures
When applying the concept 51440002 | Right and left| as the value for the 272741003 | Laterality| attribute, the transformation should be done in accordance with the modeling applied to the content in the International Edition of SNOMED CT.
This means that the transformation steps described above should be applied twice; one for each lateral half, as illustrated in the example below.
Examples of CTU expressions and their evaluation at level 1.
Accept
=== 14600001000004107 |Closure of wound of ankle with flap| : { 260686004 |Method| = 129357001 |Closure - action| , 405813007 |Procedure site - Direct| = ( 344001 |Ankle region structure| : 272741003 |Laterality| = 7771000 |Left| ), 363700003 |Direct morphology| = 13924000 |Wound| , 424361007 |Using substance| = 256683004 |Flap| }
Accept
=== 449647000 |Reduction of open fracture of lower leg with internal fixation| : { 260686004 |Method| = 129371009 |Fixation - action| , 405813007 |Procedure site - Direct| = ( 702468001 |Bone structure of lower leg| : 272741003 |Laterality| = 7771000 |Left| ), 363700003 |Direct morphology| = 52329006 |Fracture, open| , 363699004 |Direct device| = 31031000 |Orthopedic internal fixation system, device| } { 260686004 |Method| = 129427006 |Reduction - action| , 405813007 |Procedure site - Direct| = ( 702468001 |Bone structure of lower leg| : 272741003 |Laterality| = 7771000 |Left| ), 363700003 |Direct morphology| = 52329006 |Fracture, open| }
Reject
N/A
Accept
=== 52734007 |Total replacement of hip| : { 260686004 |Method| = 425362007 |Surgical insertion - action| , 405814001 |Procedure site - Indirect| = ( 182201002 |Entire hip joint| : 272741003 |Laterality| = 7771000 |Left| ), 363699004 |Direct device| = 304120007 |Total hip replacement prosthesis| } { 260686004 |Method| = 257903006 |Repair - action| , 405813007 |Procedure site - Direct| = ( 182201002 |Entire hip joint| : 272741003 |Laterality| = 7771000 |Left| )}
Adding Context to Clinical Findings
At level 1, the terminology server will accept CTU expressions matching the following pattern:
This pattern allows attributes applicable to the 413350009 | Finding with explicit context (situation)| domain to be used to add contextual information to clinical finding concepts.
Important Notes
The terminology server will only accept expressions complying to this pattern if the focus concept of the CTU expression has the following characteristics:
The focus concept
is the concept 404684003 |Clinical finding| or a subtype hereof
For each expression, only one instance of each attribute is accepted
The value of the attribute must be within the allowed range of the attribute as specified by the MRCM
The generated classifiable form must be based on the following expression with 413350009 | Finding with explicit context (situation)| as the focus concept and the following default attributes and values unless otherwise specified by the CTU. The value of the Associated finding attribute will be replaced by the focus concept of the CF expression.
Examples of CTU expressions and their evaluation at level 1.
Reject
N/A
Accept
=== 413350009 |Finding with explicit context| : { 246090004 |Associated finding| = 363358000 |Lung cancer| , 408729009 |Finding context| = 415684004 |Suspected| , 408732007 |Subject relationship context| = 410604004 |Subject of record| , 408731000 |Temporal context| = 410512000 |Current or specified time| }
Accept
Adding Context to Procedures
At level 1, the terminology server will accept CTU expressions matching the following pattern:
This pattern allows attributes applicable to the 29125009 | Procedure with explicit context (situation)| domain to be used to add contextual information to procedures.
Important Notes
The terminology server will only accept expressions complying to this pattern if the focus concept of the CTU expression has the following characteristics:
The focus concept
is the concept 71388002 |Procedure| or a subtype hereof
For each expression, only one instance of each attribute is accepted
The value of the attribute must be within the allowed range of the attribute as specified by the MRCM
The generated classifiable form must be based on the following expression with 29125009 | Procedure with explicit context (situation)| as the focus concept and the following default attributes and values, unless otherwise specified by the CTU. The value of the Associated procedure attribute will be replaced by the focus concept of the CF expression.
Examples of CTU expressions and their evaluation at level 1
Accept
=== 129125009 |Procedure with explicit context| : { 363589002 |Associated procedure| = 42125001 |Excisional biopsy of breast mass| , 408730004 |Procedure context| = 410525008 |Needed| , 408732007 |Subject relationship context| = 410604004 |Subject of record| 408731000 |Temporal context| = 410512000 |Current or specified time| }
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