what does interoperability means in terms of the richness of the data when it comes to CDA documents? the CDA document has 3 levels of interoperability:
- level1: CDA header + body of unstructured blob (pdf for example)
- level2: CDA header + xml with narrative blocks, each block is code identified
- level3: CDA header + xml with narrative blocks + entries (SNOMED, CPT, ICD-9 encoded etc)
as you can see, the richness of the data grows with each level and so does the capabilities of interoperability and quality of use. the coding for level2 and level3 is a requirement and adds clarity and consistency to the transaction. moreover, with level3, entries are encoded at varying levels of specificity, which is what HL7 refers to as “incremental semantic interoperability”, which allows the vertical and easy way into implementing the standards. as interoperability goes, the richness of the data is as important as the ability to exchange it, thus CDA level3 is what HIS should strive for, which will yield better care all across.