HL7 CSU_C09 (Scheduled Clinical Study Data) | Integration Soup HL7 Reference Guide

HL7 CSU_C09 Scheduled Clinical Study Data Report

A clinical trial system reports data for a scheduled study time point.

HL7 message structure CSU_C09 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
CSU_C09.PATIENT	Patient group	Yes	Yes
PID	Patient Identification	Yes	No
PD1	Patient Additional Demographic	No	No
NTE	Notes and Comments	No	Yes
CSU_C09.VISIT	Visit group	No	No
PV1	Patient Visit	Yes	No
PV2	Patient Visit - Additional Information	No	No
CSR	Clinical Study Registration	Yes	No
CSU_C09.STUDY_PHASE	Study Phase group	Yes	Yes
CSP	Clinical Study Phase	No	No
CSU_C09.STUDY_SCHEDULE	Study Schedule group	Yes	Yes
CSS	Clinical Study Data Schedule Segment	No	No
CSU_C09.STUDY_OBSERVATION	Study Observation group	Yes	Yes
ORC	Common Order	No	No
OBR	Observation Request	Yes	No
CSU_C09.TIMING_QTY	Timing Quantity group	No	Yes
TQ1	Timing/Quantity	Yes	No
TQ2	Timing/Quantity Relationship	No	Yes
OBX	Observation/Result	Yes	Yes
CSU_C09.ORCRXARXR_SUPPGRP	Orcrxarxr Suppgrp group	Yes	Yes
ORC	Common Order	No	No
CSU_C09.RXARXR_SUPPGRP	Rxarxr Suppgrp group	Yes	Yes
RXA	Pharmacy/Treatment Administration	Yes	No
RXR	Pharmacy/Treatment Route	Yes	No

CSU_C09 is a clinical study data update message for automated reporting intervals, such as monthly or protocol-defined submissions. You will see it in older clinical trial and sponsor-reporting interfaces more often than in ordinary hospital ADT/order/result traffic.

The practical idea is simple: identify the patient and study, identify the study phase and scheduled time point, then send the observations or administrations that satisfy that time point.

A small CSU C09 example

MSH|^~\&|TRIALS|CITYHOSP|SPONSOR|REMOTE|20260728110000||CSU^C09^CSU_C09|CSUC090001|P|2.5.1 PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L||19800314|F CSR|STUDY-2026-07^SPONSOR|ALT-77^CITYHOSP|CITYHOSP^City Hospital^L|SUBJ-10045^^^SPONSOR^AN||20260718113000|7788^Trial^Tara|9911^Oncologist^Owen CSP|CYCLE1^Cycle 1^L|20260718113000 CSS|DAY-28^Day 28 assessment^L|20260728100000 OBR|1||STUDYLAB001^TRIALS|CBC^Complete blood count^L|||20260728100000 OBX|1|NM|WBC^White blood cells^L||6.2|10*9/L|||||F RXA|0|1|20260728103000|20260728103000|TRIALDRUG^Trial drug dose^L|1|TAB^tablet^UCUM RXR|PO^Oral^HL70162

What systems do with it

A trial or data-capture system sends CSU_C09 when a reporting interval is due. The receiver may be a sponsor gateway, research data warehouse, safety system, or internal monitoring application. Receivers usually key off the study ID, subject ID, phase, and schedule point before looking at the clinical data.

The data can look familiar because it uses segments also seen in ordinary clinical messages: OBR and OBX for observations, plus RXA and RXR for administrations. The trial wrapper is what changes the meaning.

How to read the structure

PID identifies the patient. Optional PD1, NTE, PV1, and PV2 can add demographic and visit context.

CSR identifies the study registration. CSP identifies the study phase. CSS identifies the scheduled time point. Then the repeating observation and administration groups carry the data that belongs to that schedule.

Implementation traps

The common mistake is validating the OBR/OBX or RXA/RXR content and ignoring the schedule. In clinical trial reporting, an otherwise good lab result can be rejected because it is attached to the wrong phase or scheduled time point.

Also be explicit about corrections. If a monthly report is resent with corrected observations, the receiver needs a clear replacement or correction rule. CSU_C09 itself does not magically solve study-data versioning.

Reference notes

HL7 v2 clinical study administration defines CSU_C09 for automated time-interval study reporting and uses CSR, CSP, CSS, observation, and administration groups to bind data to trial context. This page keeps the guidance intentionally short because CSU_C09 is a specialized legacy workflow.