[Geoff]

Hi Brian, I think you are as we say in the U.K. "Nit picking" insulin is produced to a International standard. so as Bluesky inferred, the effect has to measured against something. So as I see the interpretation, it is a method that you can use to calibrate what the standard produced 1 unit of insulin will have on your personal system.

In answer to your question "how old is the study" the definition comes from a book that was published in 2004, and as I said in a past posting, if anyone wants to read the book, Pm me, and I will send you a copy in pdf format.