HL7 CTI Clinical Trial Identification

Clinical study and trial fields from experience.
HL7 field reference CTI fields from HL7 v2.5.1 Show fields

These are the generated fields for the version selected at the top of the page. The document stays the same, but the reference panel follows that version.

Fields

FieldNameRequiredRepeatableTypeTable
CTI.1 Sponsor Study ID Yes No EI
CTI.2 Study Phase Identifier No No CE
CTI.3 Study Scheduled Time Point No No CE

CTI identifies the clinical trial tied to an order, observation, or result so trial-related processing can stay separate from routine care.

The standard describes CTI this way: The CTI segment is an optional segment that contains information to identify the clinical trial, phase and time point with which an order or result is associated.

Clinical-study segments tie a message back to a trial, phase, schedule, subject registration, and protocol-specific events. They are not general observation notes; they support trial governance and reporting.

The useful data is usually the combination of study identifiers, phase identifiers, schedule timing, and subject status. Keep protocol codes and local study IDs aligned with the system that is managing the trial.

The v2.5.1 structures show CTI in OMG_O19 - OMG - General clinical order, OML_O21 - OML - Laboratory order, OML_O33 - OML - Laboratory order for multiple orders related to a single specimen, and OML_O35 - OML - Laboratory order for multiple orders related to a single container of a specimen, and 12 other message structures. That tells you where it can appear, but the implementation guide still decides which optional fields are meaningful.

For practical interface work, read the generated field panel for datatype, required, repeatable, and table details, then use the notes below to decide what the field should mean in the receiving workflow.

CTI-1 Sponsor Study ID RequiredR SingleS TypeEI

CTI-1 identifies the Sponsor Study ID for this study workflow. Send the identifier that the receiving system actually keys on, and keep the assigning authority or coding system visible when the datatype supports it.

CTI-2 Study Phase Identifier OptionalO SingleS TypeCE

CTI-2 identifies the Study Phase Identifier for this study workflow. Send the identifier that the receiving system actually keys on, and keep the assigning authority or coding system visible when the datatype supports it.

CTI-3 Study Scheduled Time Point OptionalO SingleS TypeCE

CTI-3 is a timing field. Send the real source-system precision, do not pad unknown dates or times, and agree how timezone offsets are handled when time of day matters.

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