1. IHTSDO Observables Project Call
November 26, 2012
Brief introduction to the US VHA LEGO Project (an opportunity to apply the new observables model to the "real world“)
Questions on using specific attributes in the new observables model

2. Brief project introduction
Sponsored by US Veteran’s Health Administration (VHA)
Explores the feasibility of applying an experimental information model (called the SIM or Simple Integrated Model) to VHA Structured Data Entry Forms.
Focused on modeling the multiple-choice questions and answers of the VHA Progress Note Construction Set (PNCS) into simple, consistent, accurate, and complete units, known as LEGOs (Lightweight Expressions of Granular Objects).

3. Basic LEGO structure in XML
<lego> <assertion> <discernible> <concept> <rel> </rel> </concept> </discernible> <qualifier /> <value /> <timing /> <assertionComponents/> </assertion> </lego>
SNOMED CT observable entity concepts with nested relationships, similar to a SNOMED CT expression in the compositional grammar
Using the new observables model (to avoid obsolescence)
Classifiable by extensions to existing SNOMED CT Description Logic (DL)

4. Work with the Observables Project Group
To ensure that the new observables model is correctly and consistently applied to LEGOs.
To gain experience with applying the new observables model in the “real world.”
To suggest concepts that should be added to SNOMED CT in order to serve as role values.
To identify areas where revisions to the new observables model may be warranted.

5. Modeling non-laboratory observables
Many LEGOs must represent non-laboratory observables. Are any additions to the model for such cases currently under discussion?
Is there a subset of attributes typically used for modeling non-laboratory observables?
PROPERTY TYPE?
INHERES IN?
INHERENT LOCATION?
TOWARDS?
Others?

6. Use of the PROPERTY TYPE attribute
Every example in the Observables Style Guide seems to have a PROPERTY TYPE attribute. Is this attribute required?
Many LEGO observables do not have an obvious property type such as color or depth. An example is "decubitus ulcer of the left heel.“
In such cases, would "Presence" be an appropriate PROPERTY TYPE? Or would it be preferable to omit the PROPERTY TYPE entirely?

7. Use of INHERES IN and INHERENT LOCATION attributes
Can either of these be used without a Property Type attribute?
There are cases where a morphologic abnormality (decubitus ulcer) must be connected to an anatomic site (left heel). Should INHERES IN typically be used with the morphologic abnormality and INHERENT LOCATION be used with the anatomic site?

8. Use of the TOWARDS attribute
The Observables Style Guide says: “This attribute is used to specify the third element of a relational quality, the first two elements being the type of property and the entity in which the quality inheres.”
Further clarification of how to use this attribute (especially for non-laboratory observables) would be appreciated…

9. Discussion of group process going forward
Goals from LEGO project perspective
Ensure that LEGO modeling reflects current thinking on new observables model
Provide feedback to group on difficult use cases encountered during LEGO modeling.
Accommodate aggressive deliverable schedule for LEGO production
Avoid disrupting work of current Observables Project Group