SOAP/CDA Protocol

The SOAP/CDA protocol enables real-time Clinical Documentation Improvement (CDI) services. This implementation follows the Epic-integrated NoteReader CDI specification for analyzing clinical notes and extracting structured data.

Overview

Clinical Documentation workflows communicate using CDA (Clinical Document Architecture). CDAs are standardized electronic documents for exchanging clinical information between different healthcare systems. They provide a common structure for capturing and sharing patient data like medical history, medications, and care plans between different healthcare systems and providers. Think of it as a collaborative Google Doc that you can add, amend, and remove entries from.

The Epic NoteReader CDI is a SOAP/CDA-based NLP service that extracts structured data from clinical notes. Like CDS Hooks, it operates in real-time and is triggered when a clinician opts into CDI functionality and signs or pends a note.

The primary use case for Epic NoteReader is to convert free-text medical documentation into coded information that can be used for billing, quality reporting, continuity of care, and clinical decision support at the point-of-care (case study).

It is a vendor-specific component (Epic), but we plan to add support for other IHE SOAP/CDA services in the future.

When	Where	What you receive	What you send back
Triggered when a clinician opts in to CDI functionality and signs or pends a note	EHR documentation modules (e.g. NoteReader in Epic)	A CDA document containing continuity of care data and free-text clinical notes	A CDA document with additional structured data extracted by your CDI service

HealthChainAPI Integration

Use the NoteReaderService with HealthChainAPI to handle SOAP/CDA workflows:

from healthchain.gateway import HealthChainAPI, NoteReaderService
from healthchain.models import CdaRequest, CdaResponse

app = HealthChainAPI()
notes = NoteReaderService()

@notes.method("ProcessDocument")
def process_note(request: CdaRequest) -> CdaResponse:
    # Your NLP pipeline here
    processed_document = nlp_pipeline.process(request)
    return processed_document

app.register_service(notes, path="/soap")

Supported Workflows

Workflow Name	Description	Trigger	Status
`sign-note-inpatient`	CDI processing for inpatient clinical notes	Signing or pending a note in Epic inpatient setting	✅
`sign-note-outpatient`	CDI processing for outpatient clinical notes	Signing or pending a note in Epic outpatient setting	⏳

Currently supports parsing of problems, medications, and allergies sections.

API Endpoints

When registered with HealthChainAPI, the following endpoints are automatically created:

Endpoint	Method	Function	Protocol
`/notereader/`	POST	`process_notereader_document`	SOAP

Note: NoteReader is a vendor-specific component (Epic). Different EHR vendors have varying support for third-party CDI services.

Request/Response Format

CDA Request Example

<?xml version="1.0" encoding="UTF-8"?>
<ClinicalDocument xmlns="urn:hl7-org:v3">
  <typeId root="2.16.840.1.113883.1.3" extension="POCD_HD000040"/>
  <templateId root="2.16.840.1.113883.10.20.22.1.2"/>
  <id root="2.16.840.1.113883.19.5.99999.1"/>
  <code code="34133-9" displayName="Summarization of Episode Note"
        codeSystem="2.16.840.1.113883.6.1" codeSystemName="LOINC"/>
  <title>CDA Document with Problem List and Progress Note</title>
  <effectiveTime value="20240712"/>
  <confidentialityCode code="N" codeSystem="2.16.840.1.113883.5.25"/>
  <languageCode code="en-US"/>

  <component>
    <structuredBody>
      <!-- Problem List Section -->
      <component>
        <section>
          <templateId root="2.16.840.1.113883.10.20.22.2.5.1"/>
          <code code="11450-4" codeSystem="2.16.840.1.113883.6.1"
                displayName="Problem List"/>
          <title>Problems</title>
          <text>
            <list>
              <item>Hypertension</item>
            </list>
          </text>
          <!-- Entry details... -->
        </section>
      </component>

      <!-- Progress Note Section -->
      <component>
        <section>
          <templateId root="2.16.840.1.113883.10.20.22.2.65"/>
          <code code="11506-3" codeSystem="2.16.840.1.113883.6.1"
                displayName="Progress Note"/>
          <title>Progress Note</title>
          <text>
            <paragraph>Patient's blood pressure remains elevated.
            Discussed lifestyle modifications and medication adherence.
            Started Lisinopril 10 mg daily for hypertension management.</paragraph>
          </text>
        </section>
      </component>
    </structuredBody>
  </component>
</ClinicalDocument>

CDA Response Example

The response includes additional structured sections extracted from the clinical text:

<?xml version="1.0" encoding="UTF-8"?>
<ClinicalDocument xmlns="urn:hl7-org:v3">
  <!-- Header information same as request -->

  <component>
    <structuredBody>
      <!-- Original sections plus extracted medications -->
      <component>
        <section>
          <templateId root="2.16.840.1.113883.10.20.22.2.1.1"/>
          <code code="10160-0" codeSystem="2.16.840.1.113883.6.1"
                displayName="History of medication use"/>
          <title>Medications</title>
          <text>
            <list>
              <item>Lisinopril 10 mg oral tablet, once daily</item>
            </list>
          </text>
          <!-- Structured medication entries extracted by AI... -->
        </section>
      </component>
    </structuredBody>
  </component>
</ClinicalDocument>

Supported CDA Sections

Problems/Conditions: ICD-10/SNOMED CT coded diagnoses
Medications: SNOMED CT/RxNorm coded medications with dosage and frequency
Allergies: Allergen identification and reaction severity
Progress Notes: Free-text clinical documentation

Data Flow

Stage	Input	Output
Gateway Receives	`CdaRequest`	Processed by your service
Gateway Returns	Your processed result	`CdaResponse`

You can use the CdaConnector to handle conversion between CDA documents and HealthChain pipeline data containers.