1. Reconciling Issues re Performer & Assessor
06/14/2016

2. What’s raising this issue
For some time now there has been issues with the different use and purpose of the Performer and Assessor classes
There are 3 open issues in Jira related to this topic
The current effort of mapping DICOM to BRIDG is bringing a new use case that requires a change to the BRIDG model
It’s a use case we knew was out there but it had not been brought to harmonization before
So we propose addressing all the Performer/Assessor related issues at once to make sure we are consistent in our approach

3. Current Associations on Performer and Assessor in BRIDG

4. Summary of Associations
Performer – associations go to entities directly, no roles; used for everything except Observations for which it is excluded by a constraint:
Person
Organization
Device
Assessor – associations to assorted role classes plus one entity; used only on Observations:
HealthcareProvider
ResearchStaff
AssociatedBiologicEntity
Subject
Laboratory
OversightCommittee
Role of person/org/device is often not provided
Knowing roles is essential for determining relative value of observations

5. Highlighted Issues Need to cover both attribute sets
Wording implies could be subject or performer
redundant
doesn’t make sense
inconsistent

6. Related Jira Tracker Issues
Redundancy between PerformingLaboratory and Assessor
Need to have only one path between PerfObs and the laboratory that performs it
Can an observation have both a person and a device as assessor?
Many times it’s important to capture both a device and the person who operates the device, e.g. imaging, sometimes even more than one device and more than one person
The term “assessor” is not the best fit for such observations – need performer and assessor
Performer association between PerformedAdministrativeActivity and StudySite
Need to resolve redundancy and ambiguity – StudySite as Subject and as Performer
(See issue details in reference section at end of slides if interested)

7. Principles on which the change proposals are based
Redundant relationships add confusion and cause inconsistency in models and implementations (code and databases)
Cardinality on associations must support reality (more than one performer/assessor is often required, same Performer on different activities is a different performance, thus a different Performer)
Specificity supported in Assessor associations can be additional options on Performer
Any given use case needs to determine whether role-based specificity is required

8. 9/22/2016 vote at WGM: Jean moved and Julie seconded, 1 abstention, 15 for, approved
Or should we leverage Performer.typeCode to represent whether it’s a Performing or Collecting lab, drop the Perf/CollLab classes and have all associations go to Laboratory? YES, do this, drop PerfCollSpec to PerfLab/CollLab assoc
Proposed Changes
StudySite set:
Add association from Subject to StudySite
Add association from Performer to StudySite
Drop association from PerformedAdministrativeActivity to StudySite
Laboratory set:
Add association from Performer to PerformingLaboratory
Add association from Performer to CollectingLaboratory
Drop association from Assessor to Laboratory
Assessor merges into Performer set:
Move association from Assessor to HealthcareProvider to start from Performer
Move association from Assessor to ResearchStaff to start from Performer
Move association from Assessor to AssociatedBiologicEntity to start from Performer
Move association from Assessor to Subject to start from Performer
Move association from Assessor to OversightCommittee to start from Performer
Move evaluatorAlias attribute from Assessor to Performer
(association from Performer to Device is already there)
Change cardinality on the Activity end of the association from Performer to Activity to be 1, not 1..*)
Update definition of Performer – see next slide
Drop Assessor class and constraint on PerformedObservation excluding use of Performer for PerfObs
Move all tags as appropriate

9. Reconciling Performer & Assessor Definitions
Performer DEFINITION: A person, organization or device that participates in an activity. EXAMPLE(S): surgeon, performing laboratory, monitoring device OTHER NAME(S): NOTE(S):
Assessor
DEFINITION:
The person, organization, or device making an observation.
EXAMPLE(S):
healthcare provider, adjudication committee, family member, radiologist, vendor (may provide a uniform assessment for all sites participating in a study), heart rate monitor, pace maker.
OTHER NAME(S):
NOTE(S):
Performer (Proposed Updates)
DEFINITION:
The person, organization, or device that executes or accomplishes an activity.
EXAMPLE(S):
surgeon, performing laboratory, monitoring device, healthcare provider, adjudication committee, family member, radiologist, vendor (may provide a uniform assessment for all sites participating in a study), heart rate monitor, pace maker.
OTHER NAME(S): Assessor
NOTE(S): A Performer may be simply a person, organization or device or it may be a person, organization or device in a particular role that is important for understanding or interpreting the significance of the activity or its results, such as with observations.

10. For Reference
BRIDG UML Jira Issues

11. Jira Tracker Issue – BRIDGUML-31
Redundancy between PerformingLaboratory and Assessor
PerformedObservation and Laboratory can be "connected" by way of either PerformingLaboratory or Assessor. I don't understand whether there's a real difference between the use of these two classes. Neither has any attributes. There is some difference in the cardinality of the associations:
The cardinality at the PerformedObservation end of the link to Assessor is 0...* while the cardinality at the PerformedObservation end of the link to PerformingLaboratory is 1...*.
The cardinality at the Laboratory end of the link to Assesor is while the cardinality at the Laboratory end of the link to PerformingLaboratory is 1.
This difference may reflect just reflect the fact that PerformingLaboratory is used only to link PerformedObservation while Assessor is used to link one of six different classes to PerformedObservation.
If there is a real difference between the two classes I would like advice on when to use which one. Otherwise I think that PerformingLaboratory should probably be dropped.

12. Jira Tracker Issue – BRIDGUML-213
Can an observation have both a person and a device as assessor?
There are situations where we would want to know both the person or organizaition making an observation and the device used in making an observation when there is skill involved in using the process of using the equipment to make an observation. For example electrocardiography uses a device but there is quite a bit of skill in how the device is used. However each PerformedObservation is reported by one Assessor. Is there a different relationship that should be used for the device or for the person using the device?
This question originally arose in the context of spirometry where the spirometer device is clearly important but the coaching of the subject in performing the breathing maneuvers measured by the device are also important.

13. Jira Tracker Issue – BRIDGUML-26
Performer association between PerformedAdministrativeActivity and StudySite
While researching a CTR-proposed new association between Subject and a HealthcareFacility (HCF) that may play the role of Subject in an administrative activity such as audit it was discovered that there is a "performer" association between PerformedAdministrativeActivity and StudySite. This association has been in the model since BRIDG 1.0 was released so there is likely no record of where the requirement came from. Additionally the association label has remained the same throughout the release history of BRIDG so this was definitely not a case of changed semantics. It does seem somewhat redundant with the existing Performer class though.
Should this association be reconciled with the Performer class which can be played by a Person, Organization or Device? Options to consider include, but are not limited to, the following: just drop the association and say that the Organization playing the role of Performer may additionally play the role of HCF or StudySite; add an association to HCF (and possibly StudySite) from Performer to accommodate the specific semantic; make no changes.