HL7 QRY_Q01 (Immediate Query) | Integration Soup HL7 Reference Guide

HL7 QRY_Q01 Immediate Query

The older QRD/QRF query that expects the answer now.

HL7 message structure QRY_Q01 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
QRD	Original-Style Query Definition	Yes	No
QRF	Original style query filter	No	No
DSC	Continuation Pointer	No	No

QRY_Q01 is an original-mode HL7 query. It is not an event notification like an admit or a result. The sender is asking another system for information and expects an immediate response, usually a DSR_Q01 display response.

You still meet QRY_Q01 around older MPI, results, billing, and departmental systems. Newer designs usually prefer QBP query profiles, but QRY_Q01 matters when an interface is keeping an older application alive or bridging a simple screen lookup.

A small QRY Q01 example

MSH|^~\&|RADPORTAL|CITYHOSP|RESULTS|CITYHOSP|20260717101500||QRY^Q01^QRY_Q01|QRYQ010001|P|2.5.1 QRD|20260717101500|R|I|QRYQ010001|||10^RD|123456^^^CITYHOSP^MR|RES|CITYHOSP QRF|RESULTS|20260701000000|20260717235959

What workflow it represents

The requester is usually a UI, integration engine, or ancillary system that needs a small set of records from a system of record. The receiver evaluates the query and normally returns a DSR display message that echoes the query definition and carries one or more DSP lines.

Because this is original-mode query syntax, the profile agreement matters more than the segment names suggest. QRD gives the receiver the query ID, timing, quantity limit, subject, and requested topic. QRF narrows the query further, often by department, date range, or status.

How to read the structure

MSH identifies the message as QRY^Q01^QRY_Q01. QRD is required and is the real payload. QRF is optional but common when the sender needs a date range or extra filter. DSC appears when the sender is continuing a previous query rather than starting a fresh one.

Do not treat QRD-4, the query ID, as decoration. It is the practical handle that helps logs, responses, and support teams connect the request with the eventual response.

Implementation traps

The biggest trap is assuming QRD and QRF are self-describing. They are only useful when both systems agree how fields like "who subject filter" and "what subject filter" are populated. A patient MRN, accession number, order number, and account number can all look plausible in the same field.

The second trap is requesting too much. If the receiver may return a large result set, agree on quantity limits and continuation before go-live. Otherwise an innocent lookup can turn into a timeout with no useful answer for the user.

Reference notes

HL7's early query chapter describes Q01 as a query made for immediate response, with QRD and optional QRF echoed back in the display response. The same chapter describes DSC as the continuation mechanism. See HL7 v2.1 Chapter 5 and the HL7 v2+ refactored query material.