Bioequivalence and Bioavailability Forum

Dear Dan, dear Helmut!

❝ ❝ The risk for the patient that the study might show a false positive result is always 5%. Right?

❝

❝ Right.

For answering regulatory concerns it is the best answer I know .

But let us keep in mind the so called "test size" of the statistical test method used.

In many cases the test method assures an size <= 0.05, thus the test may become conservative under circumstances. Then the patient's risk is at maximum 5% and otherwise <5%.

In case of "liberal" test methods the patients risk may become >5%. Such test methods should of course not used. But sometimes you have no choice ...

Remember f.i. Potvin et.al. methods for evaluating 2-stage designs which have been chosen under the assumption that 5.2% alpha inflation are allowed, considered as negligible.
Or remember the FDA scaled ABE approach according to the progesterone guidance which leads to an alpha inflation up to 6% - 7%. See here.