A CDA document shall have at least one author. Authors could be either human (ClinicalDocument/author/assignedAuthor/assignedPerson) either devices (ClinicalDocument/author/assignedAuthor/assignedAuthoringDevice).

For definition “The author element represents the creator of the clinical document. If the role of the actor is the entry of information from his or her own knowledge or application of skills, that actor is the author. If one actor provides information to another actor who filters, reasons, or algorithmically creates new information, then that second actor is also an author, having created information from his or her own knowledge or skills.” [From Implementation Guide for CDA Release 2: Imaging Integration – UV Realm, March 2009].

According to this definition, not any device that generates the electronic document has to be considered as an author:

• a spider collecting and filtering information from different repositories, according to defined rules and policies, for the scope of creating a Patient Summary is definitely a document author (and in some cases the only one );
• an application that transforms a Patient Summary record into this CDA format may not be an author;
• For cross-border exchange purposes, a device, which modifies the concepts conveyed (e.g. applying code system mappings), should appear as one of the authors. In this case (document generated through a transformation process) the authors of the parent (original) patient summary should appear as authors as well.

Further to this, authorship can give information about the nature of Patient Summary :

• if there is a person author only, then the Patient Summary is the result of a practitioner clinical act;
• if there are device authors only, the summary was automatically generated according to well defined rules defined by the responsible organization.

The CDA standard allows to provide detailed information about what was authored by whom in the Patient Summary, allowing the specification of authorship at the whole document level, at the section level and also at the entry level. In any case it is not required to repeat this information for each of the mentioned levels, taking advantage of the context conduction propriety.
In fact “context that is specified on an outer tag holds true for all nested tags, unless overridden on a nested tag. Context specified on a tag within the CDA body always overrides context propagated from an outer tag. For instance, the specification of authorship at a document section level overrides all authorship propagated from outer tags.” (HL7 CDA R2 Standard).