HL7 ADR_A19 (Patient Query Response) | Integration Soup HL7 Reference Guide

HL7 ADR_A19 Patient Query Response

The older ADT-style answer to a patient query.

HL7 message structure ADR_A19 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

Segment	Name	Required	Repeatable
MSH	Message Header	Yes	No
SFT	Software Segment	No	Yes
MSA	Message Acknowledgment	Yes	No
ERR	Error	No	No
QAK	Query Acknowledgment	No	No
QRD	Original-Style Query Definition	Yes	No
QRF	Original style query filter	No	No
ADR_A19.QUERY_RESPONSE	Query Response group	Yes	Yes
EVN	Event Type	No	No
PID	Patient Identification	Yes	No
PD1	Patient Additional Demographic	No	No
ROL	Role	No	Yes
NK1	Next of Kin / Associated Parties	No	Yes
PV1	Patient Visit	Yes	No
PV2	Patient Visit - Additional Information	No	No
ROL	Role	No	Yes
DB1	Disability	No	Yes
OBX	Observation/Result	No	Yes
AL1	Patient Allergy Information	No	Yes
DG1	Diagnosis	No	Yes
DRG	Diagnosis Related Group	No	No
ADR_A19.PROCEDURE	Procedure group	No	Yes
PR1	Procedures	Yes	No
ROL	Role	No	Yes
GT1	Guarantor	No	Yes
ADR_A19.INSURANCE	Insurance group	No	Yes
IN1	Insurance	Yes	No
IN2	Insurance Additional Information	No	No
IN3	Insurance Additional Information, Certification	No	Yes
ROL	Role	No	Yes
ACC	Accident	No	No
UB1	UB82	No	No
UB2	UB92 Data	No	No
DSC	Continuation Pointer	No	No

ADR_A19 is the response to a QRY_A19 patient query. It wraps query status and the original criteria around one or more patient-style groups, so the requester can receive demographics, visit context, insurance, diagnoses, and other ADT-flavored information.

In a legacy interface, ADR_A19 is often the bridge between an older departmental system and a patient administration source. The response can be rich, but that richness means receivers need to know which optional groups they actually support.

A small ADR A19 example

MSH|^~\&|ADT|CITYHOSP|PORTAL|CITYHOSP|20260717102003||ADR^A19^ADR_A19|ADR190001|P|2.5.1 MSA|AA|QRY190001 QAK|QRY190001|OK QRD|20260717102000|R|I|QRY190001|||1^RD|123456^^^CITYHOSP^MR|DEM|ADT QRF|CITYHOSP|20260717000000|20260717235959 EVN|A19|20260717102003 PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L||19800314|F|||12 High Street^^Auckland^^1010^NZ^H PV1|1|O|CARD^ROOM2^^CITYHOSP

What systems do with it

The receiver of ADR_A19 usually uses the response to display demographics, select a patient, create a local shell record, or verify encounter context before another transaction happens. The sender of ADR_A19 is the patient administration source or an integration layer acting on its behalf.

The response begins with MSA, optional ERR, QAK, echoed QRD, and QRF. The repeating patient group can include PID, PD1, ROL, NK1, PV1, OBX, and many other ADT-related segments depending on the version and profile.

How to read the structure

First read the status. MSA and QAK tell you whether the original query was accepted and whether the query itself found data. Then read QRD and QRF to confirm which request this response belongs to.

PID is usually the most important returned segment. PV1 becomes important when the query is visit-specific or when the requester needs current location, patient class, or attending-provider context.

Implementation traps

Do not assume ADR_A19 contains only one patient. The structure can repeat patient response groups, and older searches can return candidates. Automated consumers need a clear rule for zero, one, and many results.

Also watch optional ADT groups. Insurance, guarantor, diagnosis, allergy, and observation segments can appear, but many receivers are not prepared to consume all of them from a query response. Decide whether to ignore, store, or reject unsupported groups.

Reference notes

HL7 v2.3.1 A19 material describes the patient query and response pair, and reference definitions show ADR_A19 as the patient query response structure. See HL7 v2.3.1 A19.