Clinical Documents with HL7 CDA

HL7 CDA – Key messages CDA is the standard for electronic exchange of clinical documents; levels 1,2,3 are different mixes of text and coded data English CDA is exploring alignment with PRSB clinical record headings CDA is technically complex, but there are easy ways to implement it There are many UK CDA projects, but little sharing of experience: HL7 UK is the venue to exchange experience Robert HL7 UK

Clinical Document Architecture (CDA) CDA is preferred method for the electronic exchange of clinical documents in the English NHS Particularly for handover documents (e.g. referral, discharge letters) Timely, accurate handover information is a key component of better care (in both health and social care) CDA includes both text and coded data: –To be read by the receiving clinician (e.g. on a browser) –To be used by clinical IT applications CDA is built on HL7 Version 3 –Therefore it is technically complex –But there are easy ways to implement it

Three Levels of CDA CDA Level 1 –CDA Header uses HL7 Version 3 (Patient, author, etc.) –CDA body can be any form of document (e.g. PDF) –This is the ITK ‘Non-coded CDA’ CDA Level 2 –CDA Header is as for Level 1 –CDA Body is structured HTML (sections, sub-sections, text, tables..) –Still no coded data CDA Level 3 –Header as for levels 1 and 2 –Coded data must be consistent with rendered text –Body structure is a ‘profile’ defined by many CDA templates

Alignment of CDA with PRSB Clinical Headings Royal Colleges have worked for several years to define standard sets of headings for clinical documents: –Reminder of what the document needs to contain –So the reader can easily find his way around it These headings have been adopted by the Professional Records Standards Body (PRSB) HSCIC have defined a CDA profile which embodies the PRSB headings (currently at CDA Level 3) Currently in draft status

CDA is Technically Complex, but can be implemented simply CDA is built on HL7 Version 3 –HL7 V3 is deeply nested XML (up to 20 deep) –Many fixed attributes to fill in (e.g. moodCode, negationInd) –Obscure generic tag names –Long learning curve But there are easy ways to write CDA: –Green CDA (much simpler XML, auto-transformed to full CDA) –CDA API (a simple API to state what the CDA should contain) And there are easy ways to read it: –Render it in a browser –Convert coded data to FHIR resources

Sharing Experience of CDA CDA is a key part of the NHS Interoperability Toolkit (ITK) –There were many CDA projects in the ISCF –Most of these were CDA Level 1, some at level 3 –English CDA profiles are quite different from other CDA profiles (historical reasons) Subjective impression: there are a lot of English CDA implementations planned or starting. But there is very little sharing of experience HL7 UK intends to be the venue to share CDA experience: –In collaboration with HSCIC –Expect announcements soon