Bioequivalence and Bioavailability Forum

Hi PVRC,

❝ If an additional group is added to the study (due to recruitment issues) instead of four groups actually planned (4 x 4 Williams design), is it necessary to include the group effect in the statistical analysis plan ??

Good question.

If this is a dossier for EU:
1. If you don't add a group effect, the regulator is likely to ask for it after submission.
2. If you do add a group effect, regulators are likely to ask you to submit a secondary analysis without it.


At the end of the day Group is a between-factor, like sequence. Thus, the discussion is quite academic if we look at the confidence interval. Another matter of course is if we, for some reason or other, take an interest in the p-value of the group effect itself or group x treatment. The latter sends shivers down my spine.