Not more than 2 sequences in full replicates [Design Issues]
Hi Mauricio,
Maybe there is one but the search function is slow those days. The data base seems to be corrupted and I didn’t have the time to repair it yet.
To clarify: By 4×2 do you mean RTRT|TRTR and by 4×4 RTRT|TRTR|RRTT|TTRR or yet another one (e.g., TRRT|RTTR|TTRR|RRTT)? The notation used by
Since both have the same degrees of freedom they should have the same efficacy.
But: IIRC, in the late 1990 Donald Schuirmann argued against more than two sequences in full replicate designs. See also Appendix B of the FDA’s guidance.
❝ I am looking for a post in this forum that explain what is the best design to replicate a bioequivalence study.
Maybe there is one but the search function is slow those days. The data base seems to be corrupted and I didn’t have the time to repair it yet.

❝ The 4x4 or 4x2? Normally, I use 4x4 this is a best choice? Or I can use 4x2 with same eficcacy?
To clarify: By 4×2 do you mean RTRT|TRTR and by 4×4 RTRT|TRTR|RRTT|TTRR or yet another one (e.g., TRRT|RTTR|TTRR|RRTT)? The notation used by
PowerTOST
is treatments × sequences × periods.library(PowerTOST)
print(as.data.frame(known.designs()[8:9, ]), row.names=FALSE)
no design df df2 steps bk bknif bkni name
6 2x2x4 3*n-4 n-2 2 1 1/4 0.2500 2x2x4 replicate crossover
7 2x4x4 3*n-4 n-4 4 1 1/16 0.0625 2x4x4 replicate crossover
Since both have the same degrees of freedom they should have the same efficacy.
But: IIRC, in the late 1990 Donald Schuirmann argued against more than two sequences in full replicate designs. See also Appendix B of the FDA’s guidance.
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png)
Helmut Schütz
![[image]](https://static.bebac.at/img/CC by.png)
The quality of responses received is directly proportional to the quality of the question asked. 🚮
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Complete thread:
- Any post about difference between 4x4 and 4x2 in bioequivalence studies? Mauricio Sampaio 2016-11-03 18:54 [Design Issues]
- Not more than 2 sequences in full replicatesHelmut 2016-11-03 19:38
- Not more than 2 sequences in full replicates Astea 2016-11-04 08:22
- Only RR is used Helmut 2016-11-11 20:52
- Not more than 2 sequences in full replicates Mauricio Sampaio 2016-11-11 18:39
- Not more than 2 sequences in full replicates Astea 2016-11-04 08:22
- Not more than 2 sequences in full replicatesHelmut 2016-11-03 19:38