Higher-order cross­overs [Power / Sample Size]

posted by sweiner – 2020-01-22 20:22 (245 d 22:35 ago) – Posting: # 21081
Views: 1,896

I would like to obtain an advice on BE study sample size estimation.
Let’s say, we are planning a 2x2 crossover study for BE, and the intra-subject coefficient of variation for our test compound, from a prior study, is 23%. The assumed geometric mean ratio is 1.00, alpha is 0.05, equivalence limits are 80%-125%, and we desire power of 80%. These criteria result in an overall sample size of 20 subjects, or 10 per sequence.
Subsequently, we want to add 2 extra dose levels of our test drug, resulting in a 4x4 crossover trial. Let’s assume that %CV and GMR are not changing, as no further data is available. For this new scenario, is it appropriate to: 1) use the original sample size of N=20 and simply divide it over 4 sequences (5 per sequence), or 2) take the original per sequence sample size of 10 and multiply by 4 to get 40 subjects overall needed? In either case 1) or 2), is there a supporting reference you can provide?

Edit: Category and subject line changed; see also this post #1 and #2[Helmut]

Complete thread:

 Admin contact
21,074 posts in 4,394 threads, 1,468 registered users;
online 3 (0 registered, 3 guests [including 2 identified bots]).
Forum time: Thursday 19:58 CEST (Europe/Vienna)

Enlightenment is man’s emergence from his self-imposed nonage
for which he himself was responsible.
Nonage is the inability to use one’s own intellect
without the direction of another.    Immanuel Kant

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz