IHE ITI Technical Framework
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3.10 PIX Update Notification [ITI-10]

This section corresponds to transaction [ITI-10] of the IHE IT Infrastructure Technical Framework. Transaction [ITI-10] is used by the Patient Identifier Cross-reference Consumer and Patient Identifier Cross-reference Manager Actors.

3.10.1 Scope

This transaction involves the Patient Identifier Cross-reference Manager providing notification of updates to patient identifier cross-reference associations to Patient Identifier Cross-reference Consumers that have registered (by configuration on the Cross-reference Manager) their interest in receiving such notifications. This transaction uses HL7’s generic ‘Update Person Information’ message to communicate this patient-centric information.

3.10.2 Use Case Roles

Actor: Patient Identifier Cross-reference Manager

Role: It serves a well-defined set of Patient Identification Domains. The Patient Identifier Cross-reference Manager manages the cross-referencing of patient identifiers across Patient Identification Domains by providing a list of patient ID “aliases” via notification to a configured list of interested Patient Identifier Cross-reference Consumers.

Actor: Patient Identifier Cross-reference Consumer

Role: Receives notifications from the Patient Identifier Cross-reference Manager of changes to patient ID aliases. Typically the Patient Identifier Cross-reference Consumer uses this information to maintain information links about patients in a different patient ID domain.

3.10.3 Referenced Standard

HL7 Version 2.5, Chapter 2 – Control, Chapter 3 – Patient Administration

Note:  HL7 version 2.5 was selected for this transaction because it was considered the most stable version that contained the functionality required by transactions [ITI-9] and [ITI-10].

3.10.4 Messages

Figure 3.10-1: Update Person Information Sequence

3.10.4.1 Update Person Information

3.10.4.1.1 Trigger Events

The Patient Identifier Cross-reference Manager shall notify a Patient Identifier Cross-reference Consumer when there is a change in a set of cross-referenced patient identifiers for any of the patient identifiers belonging to Patient Identifier Domains of interest to the consumer. The configuration of the domains of interest to a Patient Cross-reference Consumer is maintained by the Patient Cross-reference Manager.

Several notifications may have to be issued to communicate a single update to a set of cross-reference patient identifiers as required to reflect all the changes on the resulting sets of cross-reference patient Identifiers belonging to Patient Identifier Domains of interest to the Patient Identifier Cross-referencing Consumer.

The following HL7 trigger event will be used to update to the list of patient identifiers:

  • A31 – Update Person Information
3.10.4.1.2 Message Semantics

The PIX Update Notification transaction is conducted by the ADT^A31 message. The Patient Identifier Cross-reference Manager initiates this transaction whenever identifier list information is updated for a patient.

It is wholly the responsibility of the Patient Identifier Cross-reference Manager to perform the matching of patient identifiers based on the patient traits it receives. The information provided by the Patient Identifier Cross-reference Manager to Patient Identifier Cross-reference Consumers shall only contain a list of cross-referenced identifiers for the domains of interest as configured with the Patient Identifier Cross-reference Manager in two or more of the domains managed by the Patient Identifier Cross-reference Manager. Multiple notifications may need to be sent. For example:

Consumer CON_A is configured to receive update notifications for domains DOM_A and DOM_AD. Notifications are sent as follows:

  • A PIX A01 feed is sent for a patient for DOM_A. The update notification shall contain the patient identifier and assigning authority for DOM_A.
  • A PIX A01 feed is processed for DOM_AD. The Patient Identifier Cross-reference Manager cross references this patient with DOM_A. The update notification shall contain the patient identifier and assigning authority for DOM_A and DOM_AD.
  • A PIX A08 feed is processed for DOM_AD changing the patient address. The Patient Identifier Cross-reference Manager cross references determines this patient is no longer the same patient as DOM_A. Two update notifications shall be sent. One containing the patient identifier and assigning authority for DOM_A. The other one containing the patient identifier and assigning authority for DOM_AD.

The list of cross-references is not made available until the set of policies and processes for managing the cross-reference function have been completed. The policies of administering identities adopted by the cooperating domains are completely internal to the Patient Identifier Cross-reference Manager and are outside of the scope of this standard. Possible matches should not be communicated until the healthcare institution policies and processes embodied in the Patient Identifier Cross-reference Manager reach a positive matching decision.

The Patient Identifier Cross-reference Manager configuration is expected to have configuration indicating which Consumers are interested in receiving the PIX Update Notification transactions. This configuration information shall include identification of the identity consumer systems interested in receiving notifications and, for each of those systems, a list of the patient identifier domains of interest. The Patient Identifier Cross-reference Manager should account for consumers interested in all domains.

The segments of the message listed in the table below are required. Other segments are optional.

Table 3.10-1: ADT Patient Administration Message

ADT Patient Administration Message Chapter in HL7 2.5
MSH Message Header 2
EVN Event Type 3
PID Patient Identification 3
PV1 Patient Visit 3

Each message shall be acknowledged by the HL7 ACK message sent by the receiver of ADT message to its sender. See ITI TF-2: C.2.3, “Acknowledgement Modes” for the definition and discussion of the ACK message.

3.10.4.1.2.1 MSH Segment

The MSH segment shall be constructed as defined in ITI TF-2: C.2.2, “Message Control”.

Field MSH-9 Message Type shall have all three components populated with a value. The first component shall have a value of ADT; the second component shall have the value of A31. The third component shall have a value of ADT_A05.

3.10.4.1.2.2 EVN Segment

See ITI TF-2: C.2.4 for the list of all required and optional fields within the EVN segment.

3.10.4.1.2.3 PID Segment

The Patient Identifier Cross-reference Manager shall provide only those attributes within the PID segment that are required by the HL7 standard: PID-3-Patient Identifier List and PID-5-Patient Name.

The Patient Identifier Cross-reference Manager shall use the field PID-3 Patient Identifier List to convey the Patient IDs uniquely identifying the patient within each Patient Identification Domain for which a Patient ID exists for the specified patient. Each resulting ID returned in PID-3 shall include a fully qualified Assigning Authority component. In other words, the Assigning Authority component returned shall include ALL subcomponents (namespace ID, Universal ID, and Universal ID type).

To eliminate the issue of multiple name values between Patient Identifier Domains, the Patient Identifier Cross-reference Manager shall return a single space character in field PID-5-Patient Name.

A single PID segment is sent in which one repetition of PID-3-Patient Identifier List is populated for each of the identifiers in the notification. If the Patient Identifier Cross-reference Manager chooses to send multiple identifiers associated with the same domain, it shall return these identifiers grouped in successive repetitions within the PID-3-Patient Identifier List.

3.10.4.1.2.4 PV1 Segment

As is specified by the HL7 Standard, Version 2.5, the PV1 Segment is required. The required field PV1-2-patient class shall contain N (not applicable) to indicate the transmission of patient information outside the context of a visit or encounter. Other fields shall be left blank.

Table 3.10-2: IHE Profile – PV1 segment

SEQ LEN DT OPT TBL# ITEM# ELEMENT NAME
2 1 IS R 0004 00132 Patient Class

Adapted from the HL7 Standard, version 2.5

3.10.4.1.3 Expected Actions

The Patient Identifier Cross-reference Consumer, when it receives the ADT^A31 message, shall update its internal identifier information for the affected patient(s) in all domains in which it is interested whenever it receives updated identifier information that results in a change to the cross-referencing of a patient.

In the case where the returned list of identifiers contains multiple identifiers for a single domain, the Patient Identifier Cross-reference Consumer shall either use ALL of the multiple identifiers from the given domain or it shall ignore ALL of the multiple identifiers from the given domain.

This allows Patient Identifier Cross-reference Consumers capable of handling multiple identities for a single patient within a single domain (i.e., those that can correctly aggregate the information associated with the different identifiers) to do so. For those Patient Identifier Cross-reference Consumers not capable of handling this situation, ignoring the entire list of different identifiers prevents the consumer from presenting incomplete data.

3.10.5 Security Considerations

3.10.5.1 Audit Record Considerations

The PIX Update Notification Transaction is a “Patient Record” event, as defined in Table 3.20.4.1.1.1-1 with the following exceptions:

3.10.5.1.1 Patient Identifier Cross-reference Manager audit message:

Shall be able to record IHE - ITI-10 Patient Identifier Cross-reference Consumer audit message. Where:

  1. Source.ActiveParticipant.UserId: The identity of the Patient Identifier Cross-reference Manager facility and sending application from the HL7 message; concatenated together, separated by the | character.
  2. Source.ActiveParticipant.AlternativeUserId: The process ID as used within the local operating system in the local system logs
  3. HumanRequestor.UserID: Identity of the human that initiated the transaction
  4. HumanRequestor.RoleIDCode: Access Control role(s) the user holds that allowed this transaction
  5. Destination.ActiveParticipant.UserId: The identity of the Patient Identifier Cross-reference Manager facility and sending application from the HL7 message; concatenated together, separated by the | character.
  6. Patient.ParticipantObjectID: The patient ID in HL7 CX format
  7. Patient.ParticipantObjectDetail: Type=MSH-10 (the literal string), Value=the value of MSH-10 (from the message content, base64 encoded)
3.10.5.1.2 Patient Identifier Cross-reference Consumer audit message:

Shall be able to record IHE - ITI-10 Patient Identifier Cross-reference Manager audit message. Where:

  1. Source.ActiveParticipant.UserId: The identity of the Patient Identifier Cross-reference Manager facility and sending application from the HL7 message; concatenated together, separated by the | character.
  2. HumanRequestor.UserID: Identity of the human that initiated the transaction
  3. HumanRequestor.RoleIDCode: Access Control role(s) the user holds that allowed this transaction
  4. Destination.ActiveParticipant.AlternativeUserId: The process ID as used within the local operating system in the local system logs
  5. Destination.ActiveParticipant.UserId: The identity of the Patient Identifier Cross-reference Manager facility and sending application from the HL7 message; concatenated together, separated by the | character.
  6. Patient.ParticipantObjectID: The patient ID in HL7 CX format
  7. Patient.ParticipantObjectDetail: Type=MSH-10 (the literal string), Value=the value of MSH-10 (from the message content, base64 encoded)