AS 4700.1.2.5:2014 Implementation of Health Level Seven (HL7) Version 2.5 and Version 2.5.1
7.1 General
It is assumed that transactions will only be produced by sending systems after satisfying the relevant validation checks within each system and, therefore, confirming that data integrity is maintained. The trigger events are described in Clauses 7.3 to 7.64 and all are served by the ADT unsolicited update and the ACK response. A19 trigger events are served by a QRY query and an ADR (ADT response) reply.
It is recognized that different healthcare systems use different definitions of admitted patient, non-admitted patient, emergency room and recurring patient types, or handle these patients differently. Therefore, trigger events are not defined as specific to any patient type. The patient type for any visit-related information shall be specified in the patient class data element (see PV1-2) to enable each system to handle the transaction properly.
This means that both the trigger event code and the patient class should be checked in order to determine how to handle the transaction. If a certain patient class can sometimes be assigned to a bed, for example, ‘observation’ patients, then the Assigned Patient Location field (see PV1-3) should also be checked.
Both admitted and non-admitted patient trigger events are generated using most of the same trigger event codes. The meaning or interpretation of the trigger event depends on the type of patient, for example, inpatient or outpatient, as defined in HL7 Table 0004 Patient Class used in field PV1-2.
The information that is included in any of these trigger event transactions can be more than the minimum necessary to accommodate the trigger event. Any data elements that are in the data segments listed for the message can be used, and as many or as few data elements as are agreed upon during implementation can be used. The A08 trigger event should be used to update data elements that are not necessarily related to any of the other trigger events. The action to be taken, if additional data elements are supplied which are not specifically related to the trigger event, should also be agreed on prior to implementation.