Monday, October 9, 2017

Where do I find the Medication Generic Name in a CCD Document

The answer is, it depends on your CCD version:

CCDA 2.1 has this to say:
 4. SHALL contain exactly one [1..1] manufacturedMaterial (CONF:1098-7411).
     Note: A medication should be recorded as a pre-coordinated ingredient + strength + dose form (e.g., “metoprolol 25mg tablet”, “amoxicillin 400mg/5mL suspension”) where possible. This includes RxNorm codes whose Term Type is SCD (semantic clinical drug), SBD (semantic brand drug), GPCK (generic pack), BPCK (brand pack).
     1. This manufacturedMaterial SHALL contain exactly one [1..1] code, which SHALL be selected from ValueSet Medication Clinical Drug urn:oid:2.16.840.1.113762.1.4.1010.4 DYNAMIC (CONF:1098-7412).
         1. This code MAY contain zero or more [0..*] translation, which MAY be selected from ValueSet Clinical Substance urn:oid:2.16.840.1.113762.1.4.1010.2 DYNAMIC (CONF:1098-31884).

CCDA 1.1 has this to say:
 4. SHALL contain exactly one [1..1] manufacturedMaterial (CONF:81-7411).
     Note: A medication should be recorded as a pre-coordinated ingredient + strength + dose form (e.g., “metoprolol 25mg tablet”, “amoxicillin 400mg/5mL suspension”) where possible. This includes RxNorm codes whose Term Type is SCD (semantic clinical drug), SBD (semantic brand drug), GPCK (generic pack), BPCK (brand pack).
     1. This manufacturedMaterial SHALL contain exactly one [1..1] code, which SHALL be selected from ValueSet Medication Clinical Drug urn:oid:2.16.840.1.113762.1.4.1010.4 DYNAMIC (CONF:81-7412).
         1. This code SHOULD contain zero or one [0..1] originalText (CONF:81-7413).
             1. The originalText, if present, SHOULD contain zero or one [0..1] reference (CONF:81-15986).
                 1. The reference, if present, SHOULD contain zero or one [0..1] @value (CONF:81-15987).
                     1. This reference/@value SHALL begin with a '#' and SHALL point to its corresponding narrative (using the approach defined in CDA Release 2, section 4.3.5.1) (CONF:81-15988).
         2. This code MAY contain zero or more [0..*] translation (CONF:81-7414).
             1. Translations can be used to represent generic product name, packaged product code, etc (CONF:81-16875).

HITSP C32 has this to say (you can actually find this in the HITSP C83 specification):
2.2.2.8.13 Free Text Product Name Constraints
C83-[DE-8.15-CDA-1] The product (generic) name SHALL appear in the <originalText> element beneath the <code>

It's pretty clear that the preferred way to handle this changed in between CCD 1.0 (HITSP C32) and CCDA 1.1, and also that some critical information loss occurred with regard to how to record generic name between CCDA 1.1 and 2.1.  I think as industry understanding of CDA expanded, the need to express the detail about generic name probably changed, but not necessarily for the better.

If you want to include generic name, you would do it in a translation -- when you don't already list the drug using an RxNORM code from the Semantic Clinical Drug value set (generic codes) (e.g., you use a Semantic Branded Drug code).

I have two statements to make about this:

  1. Not all implementers are informaticists or would understand the distinction between types of RxNorm codes.  We (HL7) need to remember to speak to who is doing the work, not to ourselves.
  2. Brand and Generic information is already represented as relationships embedded in the RxNorm terminology itself.  The simultaneous transmission of a brand code and a generic code for that same drug simply repeats what is already present in RxNorm.  The advice I give these days would be to trust RxNorm before you trust your trading partner, and if what your trading partner tells you CONFLICTS, someone needs to go raise a red flag about inconsistent data.

   Keith