Query for Documents (QD)

The Query for Documents service provides the mechanism by which one exchange partner locates electronic health information associated with a specific patient. The service allows one system to acquire a list of documents for a given patient that exists at another HIE or system, based on a set of search criteria. The service can be viewed as receiving incoming query requests, to which it must respond, and sending outgoing queries in order to locate a patient's health information.

Note that the XCA specification has been relaxed within the Nationwide Health Information Network to support the query for, and retrieval of, dynamically generated document content.
A query is initiated from one system to another, requesting a list of available documents meeting a given set of query parameters for a particular patient for later retrieval. This query includes criteria such as a patient identifier, made available through the Patient Discovery service, as well as document metadata such as a date range, etc. Authorization assertion(s) are included in the query message as specified by the Authorization Framework specification.
The response to this query is a collection of document references referring to available documents and metadata describing each document. These references may be used in the Retrieve Documents service to access the data. The document list is returned if, and only if, the patient has been registered at one or more facilities in the HIE that is initiating the query via the Patient Discovery service, has provided consent to share data, and has had identity determined by both the initiating and responding HIEs. In this context, a "document" refers to the form of electronic health information as it is transferred between HIEs or systems, not as it is stored in an HIE or system.

CONNECT includes services to query an exchange partner(s) for documents and respond to a incoming query as well as a reference implementation of the document registry that contains the metadata against which received queries operate.