CDA Connector

The CdaConnector parses CDA documents, extracting free-text notes and relevant structured clinical data into FHIR resources in the Document container, and returns an annotated CDA document as output. It will also extract the text from the note section of the document and store it in the Document.text attribute.

This connector is particularly useful for clinical documentation improvement (CDI) workflows where a document needs to be processed and updated with additional structured data.

(Full Documentation on Clinical Documentation)

(Full Documentation on CDA Parser)

Input and Output

Input	Output	Access
CdaRequest	CdaResponse	Document.fhir.problem_list, Document.fhir.medication_list, Document.fhir.allergy_list, Document.text

Usage

from healthchain.io import CdaConnector, Document
from healthchain.models import CdaRequest
from healthchain.pipeline import Pipeline

# Create a pipeline with CdaConnector
pipeline = Pipeline()

cda_connector = CdaConnector()
pipeline.add_input(cda_connector)
pipeline.add_output(cda_connector)

# Example CDA request
cda_request = CdaRequest(document="<CDA>test</CDA>")

# Accessing CDA data inside a pipeline node
@pipeline.add_node
def example_pipeline_node(document: Document) -> Document:
    print(document.fhir.problem_list)
    print(document.text)
    return document

# Pipeline execution
pipe = pipeline.build()
cda_response = pipe(cda_request)
print(cda_response)
# Output: CdaResponse(document='<Annotated CDA XML content>')

Accessing data inside your pipeline

Data parsed from the CDA document is converted into FHIR resources and stored in the Document.fhir.bundle attribute. The connector currently supports the following CDA section to FHIR resource mappings:

CDA section	FHIR resource	Document.fhir attribute
Problem List	Condition	Document.fhir.problem_list
Medication List	MedicationStatement	Document.fhir.medication_list
Allergy List	AllergyIntolerance	Document.fhir.allergy_list
Note	DocumentReference	Document.fhir.bundle (use get_resources("DocumentReference") to access)

Configuration

The overwrite parameter in the CdaConnector constructor determines whether existing data in the document should be overwritten. This can be useful for readability with very long CDA documents when the receiving system does not require the full document.

cda_connector = CdaConnector(overwrite=True)