C-CDA (Consolidated Clinical Document Architecture)
C-CDA, the Consolidated Clinical Document Architecture, is the HL7 library of templates for structured clinical documents such as the Continuity of Care Document, discharge summary and referral note. Each document pairs a human-readable narrative with coded entries, so a receiving EHR can both display the record and import its problems, medications and allergies.
Key takeaways
- An HL7 template library on top of CDA Release 2, written in XML
- Every document has a header, sections and coded entries, each marked by a template ID
- The narrative block is what a clinician reads; the coded entries are what software imports
- ONC certification requires creating and receiving C-CDA summaries for transitions of care
- Its data content follows USCDI, the same data set behind certified FHIR APIs
What C-CDA means
C-CDA sits on top of HL7 CDA Release 2. CDA defines a generic XML clinical document; C-CDA narrows it into specific US document types, each with required sections and data. HL7 built it by consolidating earlier CDA guides from the HL7 Health Story Project, IHE and HITSP into one set of templates.
The Continuity of Care Document (CCD) is one C-CDA document type: a snapshot summary of a patient's record. Discharge summaries, referral notes, progress notes and care plans are others. People often say CCD when they mean any C-CDA document, so check the template ID before assuming which one arrived.
Agnotic Technologies builds the software that creates, receives and reconciles these documents for EHR vendors and digital health companies. Parsing real-world documents and converting CDA to FHIR are covered on our C-CDA integration page.
How do the narrative block and coded entries differ?
The narrative block is the section's text, formatted for a person to read. The coded entries carry the same facts as discrete data with codes, dates and status. C-CDA recommends that each clinical statement link its entry back to the narrative it describes.
The two can disagree. A sender may update the narrative but not the entries, or send entries with null codes. A receiver that imports only entries can miss what the clinician wrote, and one that shows only narrative cannot reconcile medications. A careful receiver reads both and logs the gaps.
Where does C-CDA fit next to FHIR and USCDI?
USCDI defines which data classes certified health IT must exchange. C-CDA carries those classes as documents; FHIR carries them as resources through APIs. Certified products have to support both, so many keep a C-CDA path for transitions of care and referrals while adding FHIR access for apps.
HL7 now plans C-CDA updates in line with the current USCDI version, so a document builder needs the same upkeep as a FHIR server when USCDI changes.
Which parts make up a C-CDA document?
The anatomy is the same for every C-CDA document type. The right column is what a receiving system usually reads from each part.
| Document part | What it holds | What a receiving system reads from it |
|---|---|---|
| Header | Patient, author, custodian, encounter and document type, under the US Realm Header | Patient matching, who sent the document and which encounter it belongs to |
| Template ID | An identifier with a version date on the document, on each section and on each entry | Which document type it is and which rules apply, before parsing anything else |
| Section | A titled part of the body, such as problems, medications, allergies or results | Where to find each data class, and whether the section is empty or marked as unknown |
| Narrative block | The section text a clinician reads, as formatted tables and lists | What to display to the user receiving the document |
| Coded entry | Discrete clinical statements with codes, dates and status | What to offer for import into the problem, medication and allergy lists |
Facts and primary sources
HL7 describes C-CDA as a library of CDA templates that harmonized earlier guides from the HL7 Health Story Project, IHE and HITSP into one set for the US Realm.
Source: HL7 C-CDA implementation guideC-CDA recommends that clinical statements include a link between the narrative (section.text) and the coded clinical data (entry).
Source: HL7 C-CDA general guidanceUnder 45 CFR 170.315(b)(1), certified health IT must create, receive, validate and display transition of care and referral summaries built on the C-CDA Continuity of Care Document, Referral Note and, for inpatient settings, Discharge Summary templates.
Source: eCFR, 45 CFR 170.31545 CFR 170.205(a) adopts the HL7 C-CDA implementation guide and its companion guide as the patient summary record standard, and prohibits the unstructured document template.
Source: eCFR, 45 CFR 170.205
Explore this on Agnotic
Where C-CDA shows up in how we build.