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RegisterIs the sequence effect mandatory? [General Statistics]
Dear D. Labes and Pankaj Mishra,
thank you for your answers. My personal feeling is that the inclusion of the sequence effect is more strongly requested by the regulator for BE studies than for other kinds of trials. This seems to me to be a quite inconsistent attitude. Do you agree with me?
However, this regulatory requirement leads me to another question: which effect should we include for the analysis of a crossover design with number of periods = number of treatments > 2 (i.e., 3x3, 4x4, etc.)?
[1]S. Senn, "Crossover Trials in Clinical Research", Second edition, Wiley 2002 (section 10.5.3, pag. 317).
thank you for your answers. My personal feeling is that the inclusion of the sequence effect is more strongly requested by the regulator for BE studies than for other kinds of trials. This seems to me to be a quite inconsistent attitude. Do you agree with me?
However, this regulatory requirement leads me to another question: which effect should we include for the analysis of a crossover design with number of periods = number of treatments > 2 (i.e., 3x3, 4x4, etc.)?
- Sequence. But how the sequence effect should be interpreted in such a design? I suppose that it captures the effect not only of first-order carryover, but also of carryover of higher orders. If I'm correct, how this can be reconciled with the FDA GL Statistical Approaches to Establishing Bioequivalence? In the section VII.B (pag. 14) it is stated that "Typically only first-order carryover effects are considered of concern".
- First-order carryover. This choice would be more consistent with the above quoted GL. I also think that it is consistent with the use of Williams designs (see also this topic, where I agree with D. Labes): "If simple carry-over applies, then Williams squares are optimal designs (...). In practice, however, if other forms of carry-over apply, such designs are not optimal (...). Deliberately choosing a Williams design, therefore, only makes sense if simple carry-over is believed to apply" [1].
[1]S. Senn, "Crossover Trials in Clinical Research", Second edition, Wiley 2002 (section 10.5.3, pag. 317).
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Kind regards,
Stefano
Kind regards,
Stefano
Complete thread:
- Is the sequence effect mandatory? vezz 2009-12-09 21:52
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Is the sequence effect mandatory? Pankaj Mishra 2009-12-10 07:21
- Sequence effect and 90% CI d_labes 2009-12-10 09:24
- Is the sequence effect mandatory? d_labes 2009-12-10 09:01
- Is the sequence effect mandatory?vezz 2009-12-10 11:02
- Treatment by period interaction d_labes 2009-12-10 16:43
- Old farts Helmut 2009-12-10 16:55
- Old farts vezz 2009-12-10 18:10
- New brooms Helmut 2009-12-10 19:19
- Give sequence a chance d_labes 2009-12-11 09:42
- Give history a chance Helmut 2009-12-11 13:40
- Old farts? d_labes 2009-12-11 09:09
- Young farts... Helmut 2009-12-11 13:51
- Old farts vezz 2009-12-10 18:10
- Old farts Helmut 2009-12-10 16:55
- Treatment by period interaction d_labes 2009-12-10 16:43
- Is the sequence effect mandatory?vezz 2009-12-10 11:02
- Is the sequence effect mandatory? Pankaj Mishra 2009-12-10 07:21
Ing. Helmut Schütz