Bioequivalence and Bioavailability Forum • Multiplicity?

Multiplicity? [Design Issues]

posted by Helmut – Vienna, Austria, 2024-11-23 14:05 (8 d 04:42 ago) – Posting: # 24295
Views: 363

Hi BEQool,

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 C_max would not be significant any more.

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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
        
        Groups BEQool 2024-11-26 08:15