Bioequivalence and Bioavailability Forum

Hi Old sailor, hi Helmut,

❝ ❝ @Detlew: Maybe PowerTOST should throw a warning if the input’s theta2 ≠ 1/theta1 (to the precision of the input)? Or is this over the top?

I'm not quite sure if this is worth a warning.
It is quite unusual to use other BE acceptance limits than theta2=1/theta1 or vice versa. But ... maybe some guy wishes to do so, for instance if a regulator deemed him to do so, see Canada "Critical dose drugs": The 90% confidence interval of the relative mean AUC* of the test to reference formulation should be within 90.0% to 112.0% inclusive.

The implemented algorithm is valid also if theta2 ≠ 1/theta1, I think.

❝ Nice idea, actually. I am anticipating a borderline grumpy reply like "Take my code and do it better." from him

Only for those who criticise peanuts while on the other hand stating "not often using PowerTOST". Thank you for not using PowerTOST. Me too since I got stuck with SAS .

@Ken: Since you have dropouts I'm sure that your data are unbalanced. Therefore I recommend you the function power2.TOST().

Key in the number of subjects in the sequence groups, the GMR (0.95?) from your study and the CV:
power2.TOST(CV=0.29, n=c(14,11), theta0=0.95)
[1] 0.6106208
I have assumed worse case that all dropouts are from the same sequence group. Note the drop of power compared to your calculation via power.TOST() which assumes balanced studies.