This page is to discuss the idea of Citations as something that is needed within openEHR. This concept will be used to meet a number of requirements:

To express that another part of the health record has been viewed and noted as a query
- Past history noted can actually point to the past history events displayed at the time
To hold and display information from another source, or part of the record or composition, as a MIME type - noting it
- A scanned in document or a part of a CDA document may need to be cited in the health record, allowing it to be displayed for reading and to be sure what the person actually had access to at the time.
To include openEHR information from elsewhere in the EHR.
- A medication order may need to be included in a prescription sent to the pharmacy if the pharmacy does not have access to the person's EHR. (Actually messages are likely to be used for this purpose for the foreseeable future but the problem is a generic one).

The CEN standard has the idea of original data and repeating the information - which does deal with one aspect of citation: when data is of a type that can be entered at the point it is to be cited (according to the CEN containment model) It does not deal with including compositions in other compositions should an entire result need to be cited or parts of compositions that are not able to be contained at the level the citation is sought.

Technically the information could be stored as one of the following:

an AQL query statement with composition version specific details (to insure that updated information was not displayed instead at a later date)
any type of MIME data such as text, HTML, pdf etc
as openEHR data

It seems that there are two appropriate means of dealing with this:

Create an admin entry archetype CITATION and provide all the features as openEHR data types
Create a new CITATION class as a special type with the features required. This class may need to behave as an entry and also as an item - something that warrants consideration.