Allows a sending system to communicate that a business rule has been intentionally overridden, carrying the override type, business rule code, override comments, and the identity of the person authorizing the override. It is placed adjacent to the segments that would trigger the overridden rule, commonly used in pharmacy dispense and order messages so that clinical decision support alerts (such as drug interaction warnings) can be acknowledged and documented.
from zato.hl7v2.v2_9 import OVR
from zato.hl7v2.v2_9 import CWE, XCN
ovr = OVR()
ovr.business_rule_override_type = CWE(
identifier='ALLERGY',
text='Allergy Override'
)How to construct and work with real-world OVR segments.
Override allergy alert
from zato.hl7v2.v2_9 import OVR
from zato.hl7v2.v2_9 import CWE, XCN
ovr = OVR()
ovr.business_rule_override_type = CWE(
identifier='ALLERGY',
text='Allergy Override'
)
ovr.business_rule_override_code = CWE(text='Patient confirmed no reaction')
ovr.override_entered_by = XCN(
id_number='12345',
family_name='Smith',
given_name='John'
)Override drug interaction alert
from zato.hl7v2.v2_9 import OVR
from zato.hl7v2.v2_9 import CWE, XCN
ovr = OVR()
ovr.business_rule_override_type = CWE(
identifier='DRUG',
text='Drug Interaction Override'
)
ovr.business_rule_override_code = CWE(text='Benefit outweighs risk')
ovr.override_entered_by = XCN(
id_number='67890',
family_name='Jones',
given_name='Mary'
)Override duplicate order alert
from zato.hl7v2.v2_9 import OVR
from zato.hl7v2.v2_9 import CWE, XCN
ovr = OVR()
ovr.business_rule_override_type = CWE(
identifier='DUP',
text='Duplicate Order Override'
)
ovr.business_rule_override_code = CWE(text='Intentional repeat order')
ovr.override_entered_by = XCN(
id_number='11111',
family_name='Brown',
given_name='Robert'
)Step-by-step guides for working with HL7 v2 in Zato.
OVR contains override information including override types, reasons, and codes for clinical decision support alerts.
Common override types include ALLERGY (Allergy Override), DRUG (Drug Interaction Override), and DUP (Duplicate Order Override).
Use business_rule_override_type field with CWE datatype:
from zato.hl7v2.v2_9 import OVR
from zato.hl7v2.v2_9 import CWE
ovr = OVR()
ovr.business_rule_override_type = CWE(
identifier='ALLERGY',
text='Allergy Override'
)OVR contains override information while ORC contains the order. OVR follows ORC when an override is needed for the order.
Populate override_authorized_by with XCN so the approving coach or registered dietitian is named next to the override for accountability.
from zato.hl7v2.v2_9 import OVR
from zato.hl7v2.v2_9 import XCN
ovr = OVR()
ovr.override_authorized_by = XCN(
id_number='COACH01',
family_name='Rivera',
given_name='Alex'
)Zato connects to any system that speaks HL7v2 over MLLP or FHIR over REST. This includes Epic, Cerner, Meditech, Allscripts, and other EHR platforms.
Yes, Zato has built-in MLLP support for sending and receiving HL7v2 messages. MLLP channels handle the framing protocol automatically.
Zato supports HL7 v2.9, which is backward compatible with earlier versions including v2.3, v2.5, and v2.7. Standard segments and datatypes are available as typed Python classes.
Yes. Zato handles both HL7v2 and FHIR natively, so you can parse v2 messages and build FHIR resources with IG-specific extensions in the same service. Typed Python classes are available for both protocols, including extensions from US Core, UK Core, Da Vinci, and other Implementation Guides.
Complete list of fields in the OVR segment, HL7 v2.9.
| # | Python name | Datatype | Usage | Repeatable | Table |
|---|---|---|---|---|---|
| 1 | business_rule_override_type | CWE | Optional | No | HL70518 |
| 2 | business_rule_override_code | CWE | Optional | No | HL70521 |
| 3 | override_comments | TX | Optional | No | - |
| 4 | override_entered_by | XCN | Optional | No | - |
| 5 | override_authorized_by | XCN | Optional | No | - |
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