Groups [Design Issues]
❝ Quite likely, esp. since agencies think that \(\small{p(G\times T)<0.05}\) is a signal of data manipulation.
❝ ❝ ❝ A new term: Hardly overlapping CIs. Again: So what? Justification?
❝ ❝ How do you plan to "justify" this difference?
❝ Well, the deadline for the response is today. I made only sarcastic comments like …As long as confidence limits overlap, treatment effects estimated in the groups do not differ significantly. To question that is like saying “since the upper confidence limit is 124%, products are hardly bioequivalent”… and suggested the applicant to translate it into a more diplomatic language.
❝ I forgot something. The GL states… applicants should evaluate potential for heterogeneity of treatment effect across groups …In my understanding »across groups« means all pairwise comparisons. Then their number increases quickly with the number of groups and PK metrics. Let \(\small{n}\) be the number of groups and \(\small{m}\) the number of PK-metrics. Then the number of pairwise comparisons is given by \(\small{k=}\frac{n!}{2\,(n-2)!}\) per metric. The familywise error rate (here the chance to observe at least one false positive in any of the tests) is given by \(\small{(1-(1-\alpha)^k})\times m\). With \(\small{\alpha=0.05}\) in my example above we get 10%. In order to counteract that we should test with \(\small{\alpha_\text{adj}=\alpha / (k\times m)}\).
❝ If that is done, the G×T interaction of Cmax would not be significant any more.
PS How do you get FWER=10%? Based on your example above m=2 (AUC and Cmax), n=2 (2 groups) and therefore k=2. With alpha=0.05 shouldnt FWER be 19.5%?
Or did you use m=1 as both AUC and Cmax should be okay (union-intersection principle) and got FWER=9.75%=10%?
BEQool
Complete thread:
- Possible reasons for group effect GM 2019-07-20 07:36 [Design Issues]
- Group “effect” Helmut 2019-07-20 14:02
- Possible reasons for group effect ElMaestro 2019-07-20 19:20
- Possible reasons for group effect GM 2019-07-23 06:23
- “Group-by-Treatment Interaction” Helmut 2019-07-23 10:32
- “Group-by-Treatment Interaction” BEQool 2024-10-22 12:39
- “Group-by-Treatment Interaction” Helmut 2024-10-22 12:47
- OT: A choice between mittyri 2024-10-22 16:03
- OT: A choice between BEQool 2024-10-23 11:02
- OT: A choice between Helmut 2024-10-23 11:58
- OT: A choice between BEQool 2024-10-23 13:17
- OT: A choice between Helmut 2024-10-23 13:22
- Groups: Overlapping CIs Helmut 2024-11-03 11:36
- Groups: Overlapping CIs BEQool 2024-11-05 09:14
- Groups: Overlapping CIs Helmut 2024-11-05 10:12
- Groups: Overlapping CIs BEQool 2024-11-06 07:44
- Groups: (Hardly‽) overlapping CIs Helmut 2024-11-21 13:20
- Groups: (Hardly‽) overlapping CIs BEQool 2024-11-22 12:32
- Groups: (Hardly‽) overlapping CIs Helmut 2024-11-22 12:58
- Multiplicity? Helmut 2024-11-23 13:05
- GroupsBEQool 2024-11-26 08:15
- Groups: (Hardly‽) overlapping CIs BEQool 2024-11-22 12:32
- Groups: (Hardly‽) overlapping CIs Helmut 2024-11-21 13:20
- Groups: Overlapping CIs BEQool 2024-11-06 07:44
- Groups: Overlapping CIs Helmut 2024-11-05 10:12
- Groups: Overlapping CIs BEQool 2024-11-05 09:14
- OT: A choice between BEQool 2024-10-23 13:17
- OT: A choice between Helmut 2024-10-23 11:58
- OT: A choice between BEQool 2024-10-23 11:02
- OT: A choice between mittyri 2024-10-22 16:03
- “Group-by-Treatment Interaction” Helmut 2024-10-22 12:47
- “Group-by-Treatment Interaction” BEQool 2024-10-22 12:39
- “Group-by-Treatment Interaction” Helmut 2019-07-23 10:32
- Possible reasons for group effect GM 2019-07-23 06:23