Bioequivalence and Bioavailability Forum

Hi Zan,

❝ As I was going to use these intrasub CV% to help biostats to est sample size for a BE study, someone challenged that these number are not real and are likely inflated due to the signficant treatment effect. Is it true? I am wondering does it invalidate the use of intrasub CV% in studies with significant tx effect or these estimates are still close to those from a replicated study.

Treatment is a fixed effect. When we maximise the likelihood of the model given the observed data, we figure out two constants for the treatments (and for the other fixed effects) which help towards minimisation of the sums of squares. A significant treatment effect is thus not causing a statistical inflation of the residual sums of squares per se but will increase the difference for the treatment LS Means or effect vector values. Or to say it differently: A treatment effect just increases the total/null/model-free sums of squares but not the residual.