Saturday, December 10, 2011

Difficult days for CDISC end-to-end

The last two-three weeks were difficult ones for the CDISC end-to-end cause.

There was a lot of discussion within the volunteer team that is developing define.xml 2.0 whether elements like "MeasurementUnit" should be allowed in define.xml 2.0. The reason is that some of the team wanted to discourage (or even forbid) the use of "MeasurementUnit" in define.xml 1.0 and future 2.0 files, as "MeasurementUnit" is not explicitely stated in the define.xml specification. Others were of the opinion that "MeasurementUnit" has always been allowed in define.xml, as define.xml is an extension of the ODM standard. Also, several vendors of software for generating define.xml files do use "Measurement" as it is the most natural way to attach information about which units were used in which tests.
The discussion however has a deeper origin. The real question is whether define.xml is part of the chain in end-to-end (i.e. is the "last mile" to the FDA), or is just something totally different for which (unfortunately?) ODM was used (or abused?). Or as one participant stated "define.xml is another animal".
The discussions were heavy: some of the team were of the opinion that (as define.xml is totally something different) not a single element or attribute of the core ODM should be allowed in ODM if not explicitely mentioned in the define.xml spec (and also refusing to have "MeasurementUnit" in the new define.xml spec), others were of the opinion that define.xml is an important part in CDISC end-to-end, and that people should be allowed to provide additional information (such as MeasurementUnit, Question, RangeCheck etc.) to a define.xml and so to the FDA, supported by an appropriate stylesheet. This information would just come from the original protocol in ODM format without needing transformations.

At the moment that a "groaning teeth" compromise was in sight, allowing people to use define.xml either way ("strict" or "loose"), everything was questioned again by a member stating "a standard that has such compromises is not a standard".

So instead of coming to an end, the heavy discussions started again.

My personal opinion (which you may have guessed already) is that define.xml is an important link in the end-to-end chain, and using ODM elements and thus information coming from the original study design has a tremendous value.

I do not know how the discussion will further evolve. The best I think is that the compromise that was ultimately reached (but gives stomache aches to almost all of us) is implemented. If not, I am afraid that the discussions will go on, and a release of define.xml 2.0 is out-of-sight for several more months.

To better explain the (visionary? although already used by several vendors) idea of end-to-end (i.e. using one transport format from protocol design to submission to the FDA) I have decided, together with a few others, to start a new blog site, which you will soon find at

It will be open to anyone having a good heart for the CDISC end-to-end case.

1 comment:

  1. This comment has been removed by a blog administrator.