The URD (Results/Update Definition) segment defines the upper-level parameters of an unsolicited results-update subscription. It tells the result-producing system when to start sending updates, how urgent they are, who the subjects are, what subject matter is in scope, where the results should be routed, and at what detail level.
Purpose
URD is the "what and to whom" of an unsolicited results-update query. A subscriber sends a query containing URD (and usually a URS selector) to register for ongoing pushes of results that match the subscription. The producing system then sends results back as they become available, scoped by the criteria captured in URD-1 through URD-7.
URD is paired with URS (Unsolicited Selection), which expresses the finer "where and when" selection filter applied to candidate results before they are pushed.
Used in
URD appears in unsolicited results-update query messages, primarily:
- QRY^R01 — and related Q-group event variants — where a subscriber registers to receive ongoing result updates.
These flow inside the general query framework documented on QRY messages. URD is typically followed by URS and, in newer query patterns, complemented by a QPD segment.
Field-by-field reference
Source: HAPI HL7v2 v2.5.1 javadocs (https://hapifhir.github.io/hapi-hl7v2/v251/apidocs/ca/uhn/hl7v2/model/v251/segment/URD.html) for sequence, name, data type, and repetition. Length is not published in the javadocs (—); Required and Table # are filled from the HL7 v2.5.1 standard where well-established.
| Seq | Name | Data Type | Length | Req | Repeat | Table # | Description |
|---|---|---|---|---|---|---|---|
| URD-1 | R/U Date/Time | ts | — | R | — | — | Effective start time of the subscription. |
| URD-2 | Report Priority | id | — | O | — | HL70109 | Priority for the push (e.g., R, S). |
| URD-3 | R/U Who Subject Definition | xcn | — | O | Y | — | Subject persons (patients, providers) in scope. |
| URD-4 | R/U What Subject Definition | ce | — | O | Y | HL70048 | Subject matter codes for results. |
| URD-5 | R/U What Department Code | ce | — | O | Y | HL70049 | Producing department codes in scope. |
| URD-6 | R/U Display/Print Locations | st | — | O | Y | — | Routing locations for the result display. |
| URD-7 | R/U Results Level | id | — | O | — | HL70108 | Level of detail (e.g., O for order, R for result). |
Most-used fields
- URD-1 R/U Date/Time anchors the subscription's effective start; pushes for results timestamped before this value are suppressed.
- URD-2 Report Priority distinguishes routine from stat pushes and lets the producer prioritise the outbound queue.
- URD-3 and URD-4 are the workhorse filters in clinical practice — subscribing for a list of patients, providers, or subject codes.
- URD-7 R/U Results Level controls verbosity: order-only, result-only, or full result details.
Version differences (2.3 to 2.8.2)
- 2.3 introduced URD with its seven-field shape for unsolicited result updates.
- 2.3.1 and 2.4 retained the field set; small refinements to associated tables (e.g., HL70109) occurred outside the segment itself.
- 2.5 and 2.5.1 keep the seven-field structure verified in the HAPI v2.5.1 javadoc.
- 2.6 onward, including 2.7, 2.7.1, 2.8, and 2.8.2, retain URD unchanged. HL7 has steered new subscription patterns toward QBP/RSP and FHIR
Subscription, but URD remains valid for legacy Q-group queries.
Common mistakes
- Omitting URD-1 R/U Date/Time and assuming the producer will use the message timestamp. The field is required and pushes will fail validation without it.
- Stuffing multiple unrelated patients into a single URD-3 repetition rather than using separate repetitions. Downstream filters expect one subject per repetition.
- Confusing URD-4 (what subject matter) with URD-5 (what department). The former is content-based, the latter is org-based.
- Setting URD-7 R/U Results Level to a value the producer does not implement. Older systems frequently support only a subset of HL70108.
Examples
Minimal URD subscribing one provider to all routine subject codes:
URD|20260610090000|R|9988^House^Greg^^^DR
Fully-populated URD covering all seven fields:
URD|20260610090000|S|9988^House^Greg^^^DR~10044^Cuddy^Lisa^^^DR|CBC^Complete Blood Count^L~BMP^Basic Metabolic Panel^L|LAB^Laboratory^L~RAD^Radiology^L|WARD_3A~ICU_2|F
Annotated breakdown:
URD Segment ID
|20260610090000 URD-1 R/U Date/Time (effective start)
|S URD-2 Report Priority (S = stat)
|9988^House^Greg^^^DR~10044^Cuddy^Lisa^^^DR URD-3 R/U Who Subject Definition (two providers)
|CBC^Complete Blood Count^L
~BMP^Basic Metabolic Panel^L URD-4 R/U What Subject Definition (two subject codes)
|LAB^Laboratory^L~RAD^Radiology^L URD-5 R/U What Department Code (two departments)
|WARD_3A~ICU_2 URD-6 R/U Display/Print Locations (two locations)
|F URD-7 R/U Results Level (F = full)
In-context excerpt — QRY registering for stat lab pushes for one provider:
MSH|^~&|EHR|MAIN|LIS|MAIN|20260610090500||QRY^Q05^QRY_Q05|MSG000351|P|2.5.1
QRD|20260610090500|R|I|QRY000351|||00010^RD|9988^House^Greg^^^DR|RES|T
URD|20260610090000|S|9988^House^Greg^^^DR|CBC^Complete Blood Count^L|LAB^Laboratory^L|WARD_3A|F
URS|@PID.3.1^EQ^P10045~@PID.3.1^EQ^P10046|202606100000|202606102359
In-context excerpt — QRY registering for routine radiology updates for two patients:
MSH|^~&|EHR|MAIN|RIS|MAIN|20260610091000||QRY^Q05^QRY_Q05|MSG000352|P|2.5.1
QRD|20260610091000|R|I|QRY000352|||00010^RD|10044^Cuddy^Lisa^^^DR|RES|T
URD|20260610090000|R|10044^Cuddy^Lisa^^^DR|XR^X-Ray^L~CT^Computed Tomography^L|RAD^Radiology^L|RAD_READING_ROOM|R
URS|@PID.3.1^EQ^P10047~@PID.3.1^EQ^P10048|202606100000|202606102359
FHIR mapping
No segment-level ConceptMap is published in the v2-to-FHIR IG for URD. The closest FHIR analogue is Subscription, whose criteria (or filterBy in R5) expresses the equivalent of URD-3/4/5 selectors and whose channel carries the routing semantics of URD-6. URD-7 detail level has no direct FHIR equivalent; granularity is controlled instead by the resource type and _elements parameter in the search criteria.
Engine considerations
- Persist URD-1 alongside the subscription record. Restarting a feed without the original effective time risks either replaying old results or skipping pending ones.
- Validate URD-2 against HL70109 early; many engines reject unknown priority codes only at routing time, which is too late.
- When fanning out by URD-3, ensure provider identifiers are normalized to the same assigning authority before matching.
- URD-6 routing locations are free-text in v2.5.1; downstream systems should treat them case-insensitively and trim whitespace.
How Vorro parses and produces URD
Vorro parses URD into a subscription record keyed by URD-1 and the repetitions of URD-3 through URD-6, applying code-table normalization on URD-2, URD-4, URD-5, and URD-7 before storing the record. When producing URD, Vorro renders the active subscription state, expanding multi-valued selectors back into HL7 repetitions and stamping URD-1 with the configured effective time so receivers can deduplicate against prior registrations.
