Clinical Study Data Object

CDO carries cumulative dosage constraints for clinical study protocols. It specifies maximum dosage limits and the time intervals over which they apply, allowing pharmacy and research systems to enforce protocol safety thresholds.

The cumulative_dosage_limit field uses the CQ (composite quantity with units) datatype:

from zato.hl7v2.v2_9 import CDO, CQ

cdo = CDO()
cdo.cumulative_dosage_limit = CQ(
    quantity='500',
    units='mg'
)

Use cumulative_dosage_limit_time_interval with a CQ datatype referencing HL7 table 0924:

from zato.hl7v2.v2_9 import CDO, CQ

cdo = CDO()
cdo.cumulative_dosage_limit_time_interval = CQ(
    quantity='7',
    units='d'
)

The action_code field accepts standard master file action codes: A (add), D (delete), and U (update):

from zato.hl7v2.v2_9 import CDO

cdo = CDO()
cdo.set_id_cdo = '1'

# A = Add a new record
cdo.action_code = 'A'

# U = Update existing record
cdo.action_code = 'U'

# D = Delete existing record
cdo.action_code = 'D'

Set both the dosage limit and the time interval together to define a complete constraint:

from zato.hl7v2.v2_9 import CDO, CQ

cdo = CDO()
cdo.set_id_cdo = '1'
cdo.action_code = 'A'
cdo.cumulative_dosage_limit = CQ(
    quantity='1000',
    units='mg'
)
cdo.cumulative_dosage_limit_time_interval = CQ(
    quantity='14',
    units='d'
)

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.