Links among documents

Depending on the document type, any instance of epSOS pivot CDA shall have a related CDA embedding the PDF representation of the original data from which the epSOS pivot has been derived (also known as “epSOS PDF”). The consumer of the epSOS services shall be able to access this epSOS PDF – if existing - any time it deems it is necessary for the document content comprehension. [epSOS PDF – epSOS pivot link]

Moreover countries shall be able: for a given epSOS pivot document, to identify the original national data/document (i.e. that in use in their national infrastructure) this CDA comes from [Original document identification]; to trace back from the eD what is the prescription dispensed, and for each dispensed item what is the prescription item supplied. [eD to eP traceability]

Hereafter how these requirements are fulfilled for the epSOS CDAs.

Original document identification

The relationship between the eP/eD/PS instance and the document (data) in use in the National Infrastructure (“original Country-A document”) is kept via the XFRM relationship [XFRM (transform) = “The current document is a transformation of the ParentDocument”].
Where the “national” document is identified by its ID as the parentDocument relatedDocument association of the (“aa-bb-cc” in the example "Example of national document identified by its ID").

N.B.: This relationship is mandatory for this guide

NOTE: Even for countries not dealing with real documents in their National Infrastructures (e.g. data collected from local databases), this mechanism could be useful to identify the collection of data used for generating the epSOS CDAs, facilitating the information backtracking. In that case the ID might be that of the epSOS friendly document or of any other kind of intermediate document used for generating the NCP document input.

epSOS PDF – epSOS pivot link

The link between the epSOS pivot and the epSOS PDF may be derived at the document level in three ways:

• (1) both have the same relatedDocument (XFRM).parentDocument
• (2) if used, both have the same setId. This value should be equal to the “national document” setId, if existing.
• (3) the pivot have a relatedDocument relationship with the epSOS PDF.

Even if no one of the allowable relationships defined by the CDA standard (XFRM, RPLC, APND) fits perfectly with the relationship existing between the pivot and the PDF CDA; the APND relationship seems to be that better describing the epSOS scenario. In fact “An addendum is a separate document that references the parent document, and may extend or alter the observations in the prior document. The parent document remains a current component of the patient record, and the addendum and its parent are both read by report recipients.”

This relationship would be therefore represented as presented in example "Example of append relationship". Where aa1-bb1-cc1 is in this example the ID of the epSOS PDF.

eD to eP traceability

Each prescription shall have its own identifier recorded in the element section[templateId/@root='1.3.6.1.4.1.12559.11.10.1.3.1.2.1']/id (see R2.1).

Each prescription item shall have its own identifier recorder in entry/substanceAdministration[templateId/@root='1.3.6.1.4.1.12559.11.10.1.3.1.3.2']/id (see R2.4)

The prescription ID and prescription item ID must be globally unique. In countries where there can be only one item per prescription, the prescription item ID must be the same as the prescription ID

The main mechanism for handling the eD and eP linkage is through the prescription item ID that can be used by the prescribing system or provider to identify the prescription to which it belongs. (see section 12.1.3.4.8 Related prescription item).

Moreover the eD document SHALL refer the prescription ID using the InFulfillmentOf relationship. Please note that the target order.id attribute IS NOT the identifier of the document instance, but that of the prescription (as order).