Validating CDA Documents

I received sample CCD files from a trading partner. I ran their sample files against the NIST validator and the first file had over 50 errors against the base CDA schema. They had used the data type PQ for all results in the results section. Some of those results were not physical quantities. Like so:

<value unit="ML/MIN/1.73M2" value=">60" xsi:type="PQ"/>

<value unit="MIU/ML" value="<2" xsi:type="PQ"/>

<value unit="UNK" value="///" xsi:type="PQ"/>

<value unit="UNK" value="NOT DETECTED" xsi:type="PQ"/>

<value unit="UNK" value="Negative" xsi:type="PQ"/>

<value unit="UNK" value="neg" xsi:type="PQ"/>

There is a LOINC code for Serum Cholesterol. All of the codes were either "0" or "UNK".

I went in and manually fixed the data type errors.

This is invalid:

<value unit="UNK" value="neg" xsi:type="PQ"/>

"neg" is not a physical quantity. Send this as a code, instead.

This is correct:


<value xsi:type="CD" code="260385009" displayName="Negative" codeSystem="2.16.840.1.113883.6.96" codeSystemName="SNOMED-CT"/>

This is invalid:

<value unit="UNK" value="pos" xsi:type="PQ"/>

"pos" is not a physical quantity. Send this as a code, instead.

This is correct:

<value xsi:type="CD" code="10828004" displayName="Positive" codeSystem="2.16.840.1.113883.6.96" codeSystemName="SNOMED-CT"/>

This is invalid:

<value unit="UNK" value="NOT DETECTED" xsi:type="PQ"/>

"not detected" is not a physical quantity. Send this as a code, instead.

<value code="260415000" codeSystemName="SNOMED-CT" displayName="Not Detected" codeSystem ="2.16.840.1.113883.6.96" xsi:type="CD"/>

This is invalid:

<value unit="MIU/ML" value="<2" xsi:type="PQ"/>

"<2" is not a physical quantity. Use interval of physical quantity as the data type, instead.

This is correct:

<value xsi:type="IVL_PQ">
<high unit="MIU/ML" value="2"></high>
</value>

This is invalid:

<value unit="ML/MIN/1.73M2" value=">60" xsi:type="PQ"/>

">60" is not a physical quantity. Use interval of physical quantity as the data type, instead.

This is correct:

<value xsi:type="IVL_PQ">
<low unit="ML/MIN/1.73M2" value="60"></low>
</value>

There are many undefined codes in the document. These need to be provided.

<code code="0" codeSystem="2.16.840.1.113883.6.12" codeSystemName="CPT-4" displayName="UNK">

<code code="UNK" codeSystem="2.16.840.1.113883.5.83" displayName="HDL CHOLESTEROL"/>

I asked the HL7 Structured Documents mailing list how they would deal with this document. Some vendors got defensive. It was an interesting exchange.



First Evidence of Meaningful Use

We recently received an email from a laboratory system that sends us results. They currently send laboratory tests to us that are coded using "local vocabulary." They asked us if we could accept LOINC codes (http://loinc.org/) in the alternate codes.

What they are proposing is adding LOINC codes to the OBX-3 Observation Identifier field. The OBX-3 data type is Coded With Exceptions (CWE), The structure of this field is:

<Identifier (ST)> ^ <Text (ST)> ^ <Name of Coding System (ID)> ^ <Alternate Identifier (ST)> ^ <Alternate Text (ST)> ^ <Name of Alternate Coding System (ID)> ^ <Coding System Version ID (ST)> ^ <Alternate Coding System Version ID (ST)> ^ <Original Text (ST)>

So, they are proposing to send their local code in the first "triplet" of the CWE and the LOINC code in the second "triplet". This would change:

OBX|1|CWE|xxxxx^Local Test Value||result goes here.....

to

OBX|1|CWE|xxxxx^LocalTestValue^L^yyyyyy-y^Loinc Test Name^LN||result goes here.....

The first three subfields of obx-3 (aka the first triplet) are the local code (xxxxx), description (LocalTestValue), and the "L" indicates a local code. The second set of subfields (aka the second triplet) are the alternate identifiers and are the LOINC code for the test (yyyyyy-y), the description of the test from LOINC, and "LN" which specifies that the alternate code comes from LOINC.

This lab has been sending local codes for its tests for many years. The meaningful use requirements of ARRA/HITECH are nudging them to use LOINC.

Who says that we are not making progress :-)

More on Meaningful Use

I wrote earlier about what Meaningful Use is and why it is important. Recall that providers will be reimbursed for purchases of certified HIT products and that they will then recieve financial incentive for the "meaningful use" of that technololgy, but all that the legislation says is that meaningful use is:

1. ePrescribing
2. participation in an HIE
3. submission of quality measures

The importance of the definition is that it is the first step in a process that involves many others.

1. The HIT Standards committee will need to select the standards and implementation guides that support meaningful use
2. The certification body (which may be CCHIT, but HHS has not confirmed this) will need to align its certification criteria with these
3. Vendors may need to adjust their EHR Systems to ensure that it meets the criteria. This may require recertification.
4. HealthCare Organizations (HCOs) that already have technology in place may need to upgrade or adjust their systems so that they can meet the meaningful use criteria. Those organizations that do not have EHRs in place will likely wait until the vendors have caught up with the certification criteria before they begin implementing.

Until the definition is published, we can guess at what they mean, and try to be ready for it.

Money becomes available for the purchase of "certified" EHR systems in October, 2010. So, the timing is extremely tight.

These dates are from the recovery.gov website:

http://www.recovery.gov/?q=content/program-plan&program_id=5299

Standards Rulemaking: Recovery Act §3004 (B) (1) - No later than December 31, 2009, HHS shall adopt and publish an initial set of standards, implementation specifications, and certification criteria. The rulemaking for this initial set of standards, implementation specifications, and certification criteria may be issued on an interim, final basis. Fully competitive contract awards will be utilized to support the impact analysis.

Milestones:

Complete Draft Rule/ Regulatory Impact Analysis. Start: 05/01/2009 End: 08/26/2009

Submit for HHS Clearance. Start: 08/26/2009 end: 09/25/2009

Clear OMB (up to 90 day process) Start: 09/25/2009 End: 12/24/2009

Publish in Federal Register. Start: 12/24/2009 End: 12/31/2009


So, if the HIT Standards Committee is to meet the deadline of submitting the list of standards that are required to support “meaningful use” (August 26), the definition has to be published very, very soon.