HL7APY - HL7 formatting

HL7APY data model

HL7 Message Hierarchy

Logical Structure:

• MSH - Message metadata
• PID - Patient info
• PV1 - Visit info
• ORC - Order Common (metadata about the order)
  • OBR - Observation Request (specific test/procedure ordered)
  • OBX - Observation Results (individual findings/values)
    • OBX - Another result
    • OBX - Another result

In hl7apy's Nested Structure:
Message

• MSH (segment)
• ORU_R01_PATIENT_RESULT (group)
  • ORU_R01_PATIENT (group)
    • PID (segment)
      • ORU_R01_VISIT (group)
        • PV1 (segment)
      • ORU_R01_ORDER_OBSERVATION (group) ← This is the container!
        • ORC (segment)
        • OBR (segment)
          • ORU_R01_OBSERVATION (group)
            • OBX (segment)
          • ORU_R01_OBSERVATION (group)
            • OBX (segment)
          • ORU_R01_OBSERVATION (group)
            • OBX (segment)

Accessing the fields in python

Get a string read into the HL7APY class with the grouping above.

from hl7apy.parser import parse_message
from hl7apy.consts import VALIDATION_LEVEL

parsed_message = parse_message(hl7_message_text, validation_level=VALIDATION_LEVEL.TOLERANT, find_groups=True)

Now to access each step we do this:

original_pid = hl7_message.ORU_R01_PATIENT_RESULT[0].ORU_R01_PATIENT.PID

original_pv1 = hl7_message.ORU_R01_PATIENT_RESULT[0].ORU_R01_PATIENT.ORU_R01_VISIT.PV1

original_orc = hl7_message.ORU_R01_PATIENT_RESULT[0].ORU_R01_ORDER_OBSERVATION[0].ORC

original_br = hl7_message.ORU_R01_PATIENT_RESULT[0].ORU_R01_ORDER_OBSERVATION[0].OBR

And on, keeping in mind that you may need to iterate through the groups. you can have multiple patients (although rare)