Bioequivalence and Bioavailability Forum

Hi all,

It's a dumb question but I might as well ask..

According to the FDA progesterone guidance, the 3-sequences for a 3-way partial replicate study (TRR) is:
TRR
RTR
RRT

I was reviewing an old study report and found out that the CRO chose the following sequences for a 3-way partial rep study; A=Test, B=Ref. I dont know why they did this but it was before my time here.
BAB (RTR)
ABB (TRR)
BBA (RRT)

Question. Would scale average BE (SCABE) computation in SAS yield different results if the period and sequence identifier for Ref1 and Ref2 are messed up (ie: CRO inadvertently used the FDA sequences for stats but used their own sequences for dosing)? Why I ask? See below...

I set up my SAS code as per FDA's example and assigned what is Ref1 and Ref2 as per CRO's BAB, ABB, BBA randomization sequences. I compared my PROC GLM SAS output for dlat to that generated by CROs and the outcome was different. The results for SCABE (theta, sWR, Critbound, Ratio) did not match those generated by the CRO.

Now comes the interesting part. When I set up my code as per FDA, exactly AS IS, meaning even the sequence and period assignment for Ref1 and Ref2 (meaning following TRR, RTR, RRT instead of CRO's BAB, ABB, BBA), I ended up getting the same SCABE results (theta, sWR, Critbound, Ratio) as the CRO's.

Thanks
John

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Edit: Category changed. [Helmut]