HL7 V2 | TRIGGER EVENT O21
OML^O21: Laboratory order
The laboratory order message: orders for lab tests, with ORC and OBR per order and specimen details where needed.
- Message type
OML· Laboratory order message- Trigger event
O21- Message structure
OML_O21· per HL7's current table 0354; older versions sometimes paired events differently- In MSH-9
OML^O21^OML_O21
Segments in OML_O21 and their FHIR resources
The segments of the OML_O21 structure as listed in the HL7 v2-to-FHIR Implementation Guide, with the FHIR resources each one maps to. Square brackets mean optional and braces mean the segment can repeat. Indented segments belong to the group above them; “required” means required whenever that group is present.
| Segment | Name | Required | FHIR resources |
|---|---|---|---|
MSH | Message Header | Yes | Bundle MessageHeader Provenance |
[{SFT}] | Software | No · repeats | Provenance |
[ UAC ] | User Authentication Credential | No | — |
[{NTE}] | Notes and Comments (for Header) | No · repeats | — |
| PATIENT group | No | ||
PID | Patient Identification | Yes | Patient Provenance |
[PD1] | Additional Demographics | No | Patient Observation |
[{PRT}] | Participation (for Patient) | No · repeats | PractitionerRole RelatedPerson |
[{NTE}] | Notes and Comments (for Patient ID) | No · repeats | — |
[{NK1}] | Next of Kin/Associated Parties | No · repeats | RelatedPerson Patient |
[{ARV}] | Access Restrictions | No · repeats | — |
| PATIENT_VISIT group | No | ||
PV1 | Patient Visit | Yes | Encounter Basic Patient Coverage |
[ PV2 ] | Patient Visit- Additional Info | No | Encounter |
[{PRT}] | Participation (for Patient Visit) | No · repeats | PractitionerRole |
| INSURANCE group | No · repeats | ||
IN1 | Insurance | Yes | Coverage |
[ IN2 ] | Insurance Additional Information | No | — |
[ IN3 ] | Insurance Additional Information, Certification | No | Coverage |
[ GT1 ] | Guarantor | No | — |
[{AL1}] | Allergy Information | No · repeats | AllergyIntolerance |
| ORDER group | Yes · repeats | ||
ORC | Common Order | Yes | ServiceRequest Provenance |
[{PRT}] | Participation (for Common Order) | No · repeats | PractitionerRole |
| TIMING group | No · repeats | ||
TQ1 | Timing/Quantity | Yes | ServiceRequest |
[{TQ2}] | Timing/Quantity Order Sequence | No · repeats | — |
| OBSERVATION_REQUEST group | No | ||
OBR | Observation Request | Yes | ServiceRequest Specimen |
[ TCD ] | Test Code Details | No | — |
[{NTE}] | Notes and Comments (for Detail) | No · repeats | ServiceRequest |
[{PRT}] | Participation (for Observation Request) | No · repeats | PractitionerRole |
[ CTD ] | Contact Data | No | — |
[{DG1}] | Diagnosis | No · repeats | Condition |
| OBSERVATION group | No · repeats | ||
OBX | Observation/Result | Yes | Observation |
[{PRT}] | Participation (for OBX) | No · repeats | Device Observation PractitionerRole |
[ TCD ] | Test Code Detail | No | — |
[{NTE}] | Notes and Comments (for Results) | No · repeats | Observation |
| SPECIMEN group | No · repeats | ||
SPM | Specimen | Yes | Specimen |
| SPECIMEN_OBSERVATION group | No · repeats | ||
OBX | Observation/Result related to specimen | Yes | — |
[{PRT}] | Participation (for Specimen Observation) | No · repeats | — |
| CONTAINER group | No · repeats | ||
SAC | Specimen Container | Yes | — |
| CONTAINER_OBSERVATION group | No · repeats | ||
OBX | Observation/Result related to container | Yes | — |
[{PRT}] | Participation (for Container Observation) | No · repeats | — |
[SGH] | Segment Group Header | No | — |
| PRIOR_RESULT group | No | ||
| PATIENT_PRIOR group | No | ||
PID | Patient Identification– previous result | No | — |
[PD1] | Additional Demographics – previous result | No | — |
[{PRT}] | Participation (for Patient Prior) | No | — |
[{ARV}] | Access Restrictions | No | — |
| PATIENT_VISIT_PRIOR group | No | ||
PV1 | Patient Visit– previous result | No | — |
[ PV2 ] | Patient Visit Add. Info – previous result | No | — |
[{PRT}] | Participation (for Patient Visit Prior) | No | — |
| ORDER_PRIOR group | No | ||
ORC | Common Order- previous result | No | — |
[{PRT}] | Participation | No | — |
OBR | Order Detail- previous result | No | — |
[{NTE}] | Notes and Comments- previous result | No | — |
| TIMING_PRIOR group | No | ||
TQ1 | Timing/Quantity | No | — |
[{TQ2}] | Timing/Quantity Order Sequence | No | — |
| OBSERVATION_PRIOR group | No | ||
OBX | Observation/Result- previous result | No | — |
[{PRT}] | Participation (for Observation Prior) | No | — |
[{NTE}] | Notes and Comments- previous result | No | — |
[SGT] | Segment Group Trailer | No | — |
[{FT1}] | Financial Transaction | No | — |
[{CTI}] | Clinical Trial Identification | No | — |
[ BLG ] | Billing Segment | No | — |
Source: HL7 Terminology (THO) 7.4.0 and the HL7 v2-to-FHIR Implementation Guide 1.0.0, published by HL7 International under CC0. Check your trading partner's specification for the values they actually send.