ADT^A08 — Update Patient Information

A patient changes address during a stay, their phone number is updated, their marital status or name is corrected: ADT^A08 is the message that notifies these demographic updates to consumer systems.

Purpose

ADT^A08 notifies a general identity or context update of an already-known patient: address, phone, marital status, corrected name, corrected administrative sex, language, religion, admission source, etc. It is the pivot message of hospital identity vigilance: every identity correction must trigger an A08 to propagate to LIS, PACS, EHR.

A08 uses the same abstract structure as A01 (ADT_A01): every segment is identical, only values change. This HL7 design decision simplifies the receiver implementation (a single ADT_A01 parser handles A01, A04, A05, A08, A11, A12, A13).

Segment structure

Structure ADT_A01 shared with A01:

ADT_A01 (reused for A08)
  MSH                    Message Header (mandatory)
  [ SFT ]                Software Segment (optional)
  EVN                    Event Type (mandatory)
  PID                    Patient Identification (mandatory) — carries new values
  [ PD1 ]                Patient Additional Demographics
  [ { ROL } ]            Role
  [ { NK1 } ]            Next of Kin
  PV1                    Patient Visit (mandatory) — current visit context
  [ PV2 ]                Patient Visit - Additional Info
  [ { ROL } ]
  [ { DB1 } ]
  [ { OBX } ]
  [ { AL1 } ]
  [ { DG1 } ]
  [ DRG ]
  [ { PR1 [ { ROL } ] } ]
  [ { GT1 } ]
  [ { IN1 [IN2] [IN3] } ]
  [ ACC ]
  [ UB1 | UB2 ]
  [ PDA ]

MSH — Message Header

• MSH-9: ADT^A08^ADT_A01.
• MSH-12: 2.5.1.
• Otherwise identical to A01.

EVN — Event Type

• EVN-1: A08.
• EVN-2: HIS-side update timestamp.
• EVN-4: reason (table 0062, optional).
• EVN-5: operator (typically an admissions desk clerk).

PID — Patient Identification

Carries the new values. Typically updated fields:

• PID-5: name (correction, marriage, gender transition).
• PID-7: date of birth (correction).
• PID-8: sex (administrative correction).
• PID-11: address(es).
• PID-13: home phone(s).
• PID-14: business phone(s).
• PID-16: marital status (table 0002).
• PID-17: religion (table 0006).
• PID-22: ethnicity.

PID-3 (identifiers) must never change in an A08: for identifier merge, use A40 (Merge Patient — Patient Identifier List).

PV1 — Patient Visit

Reflects the current visit: visit number, class, physician, service. PV1 is typically not modified by A08 (unless the PID update is triggered during a stay).

Real-world example

Update of John Doe's record during ICU stay: he just got divorced (marital status W=Widowed or D=Divorced), moved to 250 New Street Apt 5B and has a new phone:

MSH|^~\&|HIS|HOSP01|EHR|CLINIC02|20260514120000||ADT^A08^ADT_A01|MSG00000080|P|2.5.1|||AL|NE
EVN|A08|20260514120000|||REGCLERK^Clerk^Registration^^^MS.
PID|1||MRN567890^^^HOSP^MR||DOE^JOHN^A^^MR.||19720515|M||W|250 NEW STREET^APT 5B^ANYTOWN^CA^90210^USA||(555)555-9999~^NET^Internet^john.doe.new@example.org|||M||ACCT123456|123-45-6789
PV1|1|I|ICU^101^A^HOSP01|EM|||DRSMITH^Smith^James^A^^DR.|||CAR|||1|||DRSMITH^Smith^James^A^^DR.|ADM|VIP||||||||||||||||||HOSP01|||||20260514102530

• MSH: HIS HOSP01 to EHR CLINIC02, A08, 2.5.1.
• EVN: A08 recorded at 12:00 by REGCLERK (admissions desk).
• PID: same identifiers (MRN567890), new marital status (W), new address, two contacts — a landline (555-9999) and a new email address.
• PV1: identical to the original A01 — the ICU stay continues, the implicit visit number VISIT00789 is unchanged.

A08 vs A31 vs A47

Common errors

• Modifying PID-3 in an A08: identifiers must stay stable. To merge, use A40.
• A08 without an open stay context: A08 is designed for in-stay use. Outside, use A31.
• Cascading multiple updates: if address, phone, and marital status change at the same time, a single A08 must carry all new values, not three separate A08s.
• No propagation to LIS/PACS: A08s are often dropped in routing. Verify they are broadcast to every consumer system.
• Partial PID: in HL7 v2.5+, the A08 must carry the full updated PID (replacement), not only modified fields. Fields not sent are blanked per the receiver's table-0102 handling.

Related ADT events

See also: ADT^A01 for the initial admission, and FHIR Patient for the REST/JSON equivalent where update is simply PUT /Patient/[id].