The certification regulations associated with
Meaningful Use Stage 1 (§ 170.205) called for using the HITSP C32 as the specification for the Continuity of Care Document (CCD). The NPRM for
Stage 2 points to a different
source for specifications,
the HL7 Consolidated Clinical Document Architecture
(CCDA — officially known
as HL7 document
CDAR2_IG_IHE_CONSOL_R1_DSTU_2011DEC). HL7 members can download the document from www.hl7.org. This might be interpreted as little but an
updated CCD specification.
However, the fine print in the regulation
belies a very different
approach to certification
and interoperability in Stage 2.
Both the
CCDA and the new regulatory
approach have a lot of pluses. In this blog I hope to give a “Sunday supplement” (highly simplified)
overview of the CCDA. A future
blog will build on this blog to discuss
the new regulatory
approach.
For those who wan’t an intensive
discussion on the technological
applicability of the CCDA a highly recommend the classes
offered by HL7 and a series of posts by Keith Boone in hisMotorcycle Guy blogs.
The Consolidated CDA is one of the
finest examples I have
seen of of organizing a slew of separate
specifications into a coherent and consistent set of specifications. It represents a
prodigious amount of work in the HL7 Structured Documents Work Group, many others in HL7, the S&I framework, IHE
and the Health Story Project. I suspect that ONC was actively working in the
background to push the various
organizations to solve intellectual propert and cultural issues that made prior
collaboration more difficult.
Previously
documents based on the
HL7 Clinical Document Architecture were individual specifications
developed by different
consensus groups.
Although the CDA did impose some consistency on all such documents the individual
groups often approached
the representation of clinical data differently, in terms of the sections of a document and in terms of how individual data items such as
vital signs or lab orders were represented.
As illustrated in Figure 1 the CCDA represents revised specifications
of 9 major types of documents
based on a consistent
framework of document sections and representation of different types of structured clinical data. The
templates in the box are just what you would expect templates to be, a skeleton
for positioning a group of data items inside an XML document. There are big templates
(such as the CCD or a discharge summary), “middle-sized” templates (such the
header or as one that shows how to organize allergy information) and
little templates that represent
how specific data elements
are represented (such as an allergen or the severity of an allergic reaction).
