The HL7 MDM message helps manage medical records by transmitting new or updated documents, or by transmitting important status information and/or updates for the record. Trigger events and messages can be one of two categories: they can either describe the status of the document, or they can describe the status of the document AND contain the document contents. MDM messages can be created in relation to an order or independently of them.
There are 11 different trigger events for the MDM message type provided in the HL7 standard. The most commonly used MDM message is the MDM-T02 (Original document notification and content) because it acts like an ORU (Result) message. By definition, the MDM-T02 message notifies a system of creation of a document and includes the document contents.
The OBX segment is an important part of MDM messages that contain document contents, because it is used to separate the body contents along places where headings or other separations might occur. All MDM messages have the same message structure with the exception of the OBX segment. Message types that contain document contents are significantly longer, and may have repeating OBX segments depending on how much data needs to be conveyed.
The segments in the MDM-T02, T04, T06, T08 and T10 (which all contain document contents) are as follows:
SEGMENT/ GROUP
NAME
OPTIONAL/REPEATABLE?
MSH
Message header
Required
EVN
Event type
Required
PID
Patient identification
Required
PV1
Patient visit
Required
TXA
Document notification segment
Required
OBX
Observation segment
Required, Repeatable
The segments in the MDM-T01, T03, T05, T07, T9 and T11 (which do not contain document contents) are as follows:
SEGMENT/GROUP
NAME
OPTIONAL/REPEATABLE?
MSH
Message header
Required
EVN
Event type
Required
PID
Patient identification
Required
PV1
Patient visit
Required
TXA
Document notification segment
Required
In HL7 pipe and hat format, the MDM-T01 (Original document notification) message would look like this:
