Real Progress on IHE and CCDA Harmonization

I've gotten to the point where I've been able to compare IHE and Consolidated CDA sections based on MDHT content.  For the most part, my findings are that most sections will not be a huge problem to decide what to do with.

There are some general rules that apply to all sections:

• section/code has a fixed value coming from LOINC
• section/title is present
• section/text is present

The latter most rule may be challenging for some sections like physical examination where subsections are present, but given that it says nothing about the fact that section/text could just contain white space, I could live with it in these cases.

For all the sections in the IHE Final Text, IHE and C-CDA agree on LOINC codes.  We don't necessarily have the SAME set of constraints listed, but that can be normalized.  This is something that just about everyone gets right.

We also agree mostly one what kinds of things belong in each section, e.g., medications in a medication section, et cetera.

The place where IHE and HL7 seem to disagree most is on the structure of a Physical Examination Section.  IHE allows it to be multi-level with subsections.  HL7 allows multiple levels, but doesn't reference the subsections any more as it did in the H&P Note, and requires section/text in the Physical Examination Section.  That's worthy of some discussion when we review this section in the future.

I have a two IHE sections that appear to be missing in the MDHT content:
Assessments Section: 1.3.6.1.4.1.19376.1.5.3.1.1.13.2.4

Procedures Section: 1.3.6.1.4.1.19376.1.5.3.1.3.12

I'll have to model those and rerun.  I'm looking forward to Friday when I can actually present and discuss something to the IHE folks who have been patiently waiting for me to present something.

Here are the major decision points we need to address (with my recommendations):

1. The rules for every section (listed above).
2. The choice of the entries optional section or entries required section (take the best match).
3. Cardinality of Family History Entries; do we match HL7 or require entries (depends on the IHE template).
4. Handling Results: IHE has requirements on content, HL7 has requirements on organizers which require content (shift to HL7 way).

My next step is to look into the entries.  I don't think we need to worry about documents.  In fact, as best I can tell, documents are national extension content.