Mauricio Sampaio ★ Brazil, 2016-11-03 19:54 (2701 d 19:51 ago) Posting: # 16769 Views: 6,166 |
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I am looking for a post in this forum that explain what is the best design to replicate a bioequivalence study. The 4x4 or 4x2? Normally, I use 4x4 this is a best choice? Or I can use 4x2 with same eficcacy? |
Helmut ★★★ Vienna, Austria, 2016-11-03 20:38 (2701 d 19:07 ago) @ Mauricio Sampaio Posting: # 16770 Views: 5,323 |
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Hi Mauricio, ❝ I am looking for a post in this forum that explain what is the best design to replicate a bioequivalence study. Maybe there is one but the search function is slow those days. The data base seems to be corrupted and I didn’t have the time to repair it yet. ❝ The 4x4 or 4x2? Normally, I use 4x4 this is a best choice? Or I can use 4x2 with same eficcacy? To clarify: By 4×2 do you mean RTRT|TRTR and by 4×4 RTRT|TRTR|RRTT|TTRR or yet another one (e.g., TRRT|RTTR|TTRR|RRTT)? The notation used by PowerTOST is treatments × sequences × periods.
Since both have the same degrees of freedom they should have the same efficacy. But: IIRC, in the late 1990 Donald Schuirmann argued against more than two sequences in full replicate designs. See also Appendix B of the FDA’s guidance. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! Helmut Schütz The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
Astea ★★ Russia, 2016-11-04 09:22 (2701 d 06:23 ago) @ Helmut Posting: # 16772 Views: 5,297 |
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Dear Helmut! If we deal with 2x4x4 of the kind TRRT|RTTR|TTRR|RRTT what variance should be used for scaling approach? — "Being in minority, even a minority of one, did not make you mad" |
Helmut ★★★ Vienna, Austria, 2016-11-11 21:52 (2693 d 17:52 ago) @ Astea Posting: # 16798 Views: 4,935 |
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Hi Astea, ❝ If we deal with 2x4x4 of the kind TRRT|RTTR|TTRR|RRTT what variance should be used for scaling approach? For the EMA (also fashionable in Russia) only the reference’s data are used anyway. Use the same fixed effect model with sequence+subject(sequence)+period like in the Q&A-document. Doesn’t matter that we have four sequences instead of two. For the FDA it should be possible as well but see the end of this post. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! Helmut Schütz The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
Mauricio Sampaio ★ Brazil, 2016-11-11 19:39 (2693 d 20:06 ago) @ Helmut Posting: # 16797 Views: 4,928 |
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Hi Helmut... ❝ To clarify: By 4×2 do you mean RTRT|TRTR and by 4×4 RTRT|TRTR|RRTT|TTRR or yet another one (e.g., TRRT|RTTR|TTRR|RRTT)? YES!!!! ❝ But: IIRC, in the late 1990 Donald Schuirmann argued against more than two sequences in full replicate designs. See also Appendix B of the FDA’s guidance. Thank you so much. Really, 2 more sequences are a waste of time to prove a bioequivalence result! |