Hi, I am looking for help regarding the execution ANOVA model in WinNonlin 6.4 of three-way cross-over bioequivalence study (3 period, 3 sequence, 3 treatment)
Used design
P1 P2 P3
S1 T1 R T2
S2 R T2 T1
S3 T2 T1 R
I strongly appreciate if someone could help me about this matter.
Susana, my understanding is that it is possible to do a three-way crossover bioequivalence (BE) analysis in WinNonlin, provided that all sequences are represented, and the subjects are evenly divided into each possible sequence group. However your dataset does not appear to meet these requirements. Typically a Williams’ design (3-treatment, 3-period, 6-sequence) is suggested, probably it’s best you go back to the statistician who wrote your SAP and discuss with them what they intended to analyse with the design. This thread may be of use to you.
In the mean time I’ve forwarded this thread to a more statistically qualified colleague to see if they can add anything. If you need some more statistical support you may be looking at consulting, in which case we will follow up via the support case you also opened on this issue and will require a copy of the project/dataset.
as Simon wrote some (including myself) prefer a six-sequence Williams’ design. However, if you don’t want to deal with first-order carry-over – a model which is considered obsolete by many – nothing is wrong with your Latin Square. Williams’ designs are mentioned in some regulatory guidelines (EU’s EMA, Brazil’s ANVISA, Australia, Russia,…).
The setup in Phoenix/WinNonlin is straightforward anyhow. In the BE object | Model | Reference Formulation select R. BE will be calculated for T1 vs R and T2 vs. R. No big deal.