Recently the question was asked “Are bone length measurements in scope for SEND?”, which leads to another interesting question: “Who gets to decide what is in scope for SEND?”. There are two parts to this. Firstly, which data were intended to be covered by the various CDISC documents, and secondly, which data do FDA require in SEND?

I often reference the ‘Scope of SEND’ section in the FDA’s Technical Conformance Guide (TCG) section As the title suggests, in this section, the FDA state as explicitly as they can, the breadth of studies they consider in scope and therefore required for submission. So, the FDA can require whatever they choose. However, this section is mainly dealing with the study as a whole. We are not down in the weeds, mulling over individual endpoints. To dig down that deep, we need to consult the CoDEx.

I know, ‘CoDEx’. It’s not the most intuitive name for a document, is it? I’ll be honest, whenever anyone asks me about it, I can never remember exactly what CoDEx stands for. I mean I know the terms Confidently Modelled, Exchange and Endpoints are in there somewhere, but I always seem to fluff my lines when trying to explain it. (The actual answer is “Confirmed Data Endpoints for Exchange”. I’m not sure why I keep thinking of the phrase ‘Confidently Modeled’?)

For those not familiar with the document, it is CDISC’s method of addressing the scope for SEND, down to the individual endpoints. Though not involved with authoring the document myself, I do remember how much care was given to the words chosen. While it was intended to define and communicate scope, it was also intended to not limit scope. By that I mean, if an endpoint was not listed as ‘in scope’ but could easily be represented in SEND, the document was not to imply that the endpoint shouldn’t be rendered in SEND. Consequently, the wording emphasized the idea that CDISC could confidently state that certain endpoints have been modelled, and therefore can be exchanged using SEND. But, just because CDISC have not confirmed that the endpoint can be exchanged in SEND, doesn’t mean it’s out of scope, and doesn’t tell us what the FDA may or may not consider as required.

So, how useful is the document, given so many caveats? Who uses it anyway? For the opening question that prompted this topic: “Are bone length measurements in scope for SEND?”, the CoDEx document states, “Although there are no examples in SENDIG, morphological measurement on specimens that result in numeric data can be modeled in this domain.

We don’t have example of exactly how to do this, but despite all the caveats we can tell from CoDEx that the endpoints are in scope. In this case, the often-overlooked CoDEx was really quite helpful.

Were you aware of the CoDEx document? Have you found it helpful? Let me know your thoughts at

‘til next time


Published by Marc Ellison

Self-confessed SEND nerd who loves geek-ing out about everything to do with SEND. Active CDISC volunteer and member of the CDISC SEND extended leadership team. Director of SEND solutions at Instem responsible for all our industry leading SEND products and services.