Clinical Trials: Representing specific data items

Athanasios Anastasiou athanasios.anastasiou at
Thu May 31 09:50:44 EDT 2012

Dear All

I am interested in understanding the way that specific data collected 
from a clinical trial would be stored in the E.H.R.

(And generally, how to associate data obtained for a particular purpose 
with an entity that describes that purpose)

Specifically, i have the following questions while some more details 
about each one are provided after the end of the message:

1) How is the information identifying a clinical trial supposed to be 
stored in the EHR? (Where would a composition describing a specific 
trial be stored in?)

2) How is it possible to "mark" some OBSERVATIONs as those acquired at a 
specific visit belonging to an arm of a specific trial? (How will this 
link be realised so that it is possible to query for all the datasets 
and subjects that participated in a specific trial? How is that done at 
the Archetype / Template level?)

3) Would a template have to be used to specialise entities such as 
PARTY_PROXY found at OBSERVATION Archetypes? (For example, the usable 
object would be IDENTIFIED_PARTY) Or is this supposed to be handled 
differently at runtime?

Looking forward to hearing from you
Athanasios Anastasiou

(Throughout this section, i will be referring to previous work by 
Christian Kohl available from:

Also, please note that wherever i am saying "Template" below, i mean 

1) From an "ontological" point of view, the subject of openEHR is the 
E.H.R. and the top level object is exactly that. From the same point of 
view, the "Clinical Trial" is an entity on its own to which various 
entries in subject E.H.Rs are going to have to refer to. The question is:

Where does an "entry" that represents a particular "Clinical Trial" get 
to live? Does it live in some special E.H.R. to which relevant 
COMPOSITIONs can refer to through LINKs? Or is it that every subject 
participating to a clinical trial would get a "ClinicalTrial" entry into 
their own E.H.Rs? (i.e. Study Definition Data is replicated)

2) Clinical Trial OBSERVATIONs must be associated with various other 
entities. For example, the data acquisition would most probably be 
performed by a specialist from some centre participating in the trial.

The OBSERVATION contains the right fields to do these associations 
(subject, provider, feeder_audit, work_flow_id). But how can i refer to 
a particular Visit within an Arm of a Clinical Trial from an 
OBSERVATION? (It's a little bit like extending OBSERVATION itself)

I suppose here that i will have to create a Composition Archetype 
"Clinical Trial Data Acquisition" and also a "Clinical Trial Action" to 
represent the two basic entities that are required in Observational and 
Interventional clinical trials.

The question is, how to refer back to the specific clinical trial visit 
from that? I can see two ways to do this:

Archetype "ClinicalTrialDataAcquisitionSession" COMPOSITION
data             SLOT of Any OBSERVATION //This is new data and it makes 
sense to have them attached directly here
fromClinicalTrial    OBJECT_REF study_identification.v1    //This is 
data that is not supposed to be replicated and it should "live" 
somewhere else...
atStudyVisit        OBJECT_REF study_visit_description.v1 //Same comment 
as above

Archetype "ClinicalTrialDataAcquisitionSession" COMPOSITION
data             SLOT of Any OBSERVATION
atStudyVisit        OBJECT_REF trial_visit_description.v1

(OR...just add "links" to this COMPOSITION to an other E.H.R. containing 
the clinical trial)

(B) requires that the clinical trial can be recovered just through the 
knowledge of the study visit.

Would that be along the right track?

3) Related to the above...I can see here how the Template fits in with 
the OBSERVATION. Any OBSERVATION includes "Subject" which is a 
PARTY_PROXY (and anyway abstract). But, in the Archetype, there is 
nothing to hint at what this PARTY_PROXY should be at run-time. I 
suppose that when it comes to using OBSERVATIONs in clinical trials, i 
will have to specify that the OBSERVATION is going to be accepting 
PERSON (which would lead to a list of subjects assigned to a centre or 
specialist)...Is that correct or would it be better if the user is 
presented with another form of choice to decide what should be 
"attached" to an OBSERVATION's "subject" field?

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