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Account for PK Parameter Units of Measure (PKUNIT) codelist
Forums: Validation Rule Suggestions
Yes, our plan is to start
Yes, our plan is to start using a PK Parameter Units of Measure (C85494) control terminology for validation of PC and PP data.
I have a question about that codelist. Is it OK to not have any TIME units for PK data? What about Tmax, T1/2 parameters?
The list is always growing
The existing PKUNIT list is simply what people have suggested up to this point. It is fairly new compared to the others. Any valid unit that qualifies PCSTRESC/N or PPSTRESC/N is fair game for adding to the standard list, as long as it is in common usage and fits the list's definition. Anyone can request new CDISC terms via the web request page, which can be found by navigating from the Terminology page on www.cdisc.org.
For good or bad, CDISC CT includes a separate Unit codelist for PK units. Unfortunately PKUNIT is not a direct subset of UNIT and there are inconsistencies between the two. For example, in the UNIT codelist, ng/mL should be expressed as the equivalent term ug/L, but in PKUNIT ng/mL is the required expression. This preferred term versus synonym disconnect is why the PK units cannot be absorbed directly into the UNIT CT.
Can OpenCDISC terminology checks be enhanced to take this disparity into account, by checking PC and PP units against PKUNIT rather than UNIT?
I do realize that the SDTM IG 3.1.2 is out of date with respect to the existence of the PKUNIT CT list; it refers only to UNIT as CT for PCORRESU/PCSTRESU/PPORRESU/PPSTRESU. Perhaps for PC and PP OpenCDISC could check against the superset of PKUNIT and UNIT?
I can create a superset in my own SDTMTerminology.txt file by renaming PKUNIT to UNIT, but then that would apply to all Unit variables in all domains.