What is the difference between HL7 V3 and CDA?

Question

What is the difference between HL7 V3 and CDA, really still I do not have an exact answer please help me

Thanks.

Answer 1

HLv2.x is a messaging protocol that was mainly based on ascii / text and also supported xml support. The problem was that HL7v2.x had the margin to configure up to about 20 percent. Therefore, several times HL7 also referred to as an open standard.

To undo the configuration, achieve consistency and enable Plug N Play messaging, RIM - Reference Information Model . This gave an object-oriented approach to the HL7 messaging standard.

Based on RIM, the CDA Clinical Document Architecture was developed. If you say that you use v3 or CDA, then they mean the same . The v3 post is entirely XML-based, not allowing scope for customization unlike v2.7.

UPDATE . This question here also contains additional information about the schemes used by v3 and CDA.

Key Differences

HL7 V2

• Not “Plug and Play” - it provides 80 percent of the interface and a framework for matching the remaining 20 percent based on interface by interface.
• Historically built in a special way, since at that time there was no other standard
• Generally provides 2.X compatibility
• A standard based on messaging, built on the basis of coding for channels and hats
• V2 is what most people think when people say "HL7"

Hl7 v3

• “Plug and Play” Approach - Less “Negotiating Framework”
• Many decades of effort over ten years reflecting “best and bright” thinking NOT backward compatible with V2
• A model-based standard based on a reference information model (RIM) ensures consistency across the standard.
• Messages in XML format.
• Clinical Document Architecture (CDA) is what most people think when people say "HL7 V3"

Example

v3

 <author> <time value="200202150730"/> <modeCode code="WRITTEN"/> <signatureCode code="S"/> <assignedEntity> <id root="2.16.840.1.113883.19.1122.3" extension="444-444-4444"/> <assignedPerson> <name> <given>Harold</given> <given>H</given> <family>Hippocrates</family> <suffix qualifier="AC">MD</suffix> </name> </assignedPerson> </assignedEntity> 

v3 is in continuous development. Even today, most healthcare applications continue to use v2.x.

Answer 2

CDA are HL7 documents, and HL7 Vx are messages. In short, CDA is aimed at human readability and machine processing, while messages are for machine processing only.

Here is a good link that describes both paradigms.

A CDA is autonomous and static, and the HL7 message describes a dynamic action on an object ( A08 , for example, to update visit data or A05 to admit a patient).

HL7 Vx messages are purely event-driven, while content (such as an OBX-5 field) may contain a static value. For example, we used ORU messages to embed the binary stream x-ray results.

Answer 3

I think you need to be more specific on HL7. You mean HL7 V2 or HL7 V3.

CDA is a specific model created using HL7V3 (and its basic reference information model) to present a clinical document. Thus, in fact, CDA is HL7v3, since it is an instance of a model created using HL7V3.

From my knowledge of CDA and the wider use of HL7V3, CDA is by far the most successful and widespread use of HL7V3.

Answer 4

CDA is a specification of HL7 v3. V3 is divided into domains, and CDA - as one specific domain for clinical documents. The Reference Information Model (RIM) version v3 is a common model for all v3-based standards, CDA is just one of these standards.

Answer 5

CDA and HL7 v 3.x are synonyms.