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derya2626 ☆ Turkey, 2015-08-19 15:47 (3166 d 04:58 ago) Posting: # 15305 Views: 7,021 |
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Hi everybody, Fisrt of all I would like to state that I am new in BE studies  This may be a simple question but I could not find enough information or advice about my question... Here is my question; There are 2 different dosages of the same test drug (T1, T2) and one dosage of reference (R). -Should I compare "T1 vs R" and "T2 vs R" in 2 anova tables? -If I make 2 anova should I adjust the alpha? -And if I adjust the alpha, does the CI change? Not 90% anymore...? *If there is any article, book etc. could you please tell me... Thanks in advance  Edit: Category changed. [Helmut] |
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d_labes ★★★ Berlin, Germany, 2015-08-20 11:36 (3165 d 09:08 ago) @ derya2626 Posting: # 15313 Views: 5,841 |
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Dear derya, ❝ *If there is any article, book etc. could you please tell me... A good reference book for the statistics involved is: Hauschke, Steinijans, Pigeot Bioequivalence Studies in Drug Development Wiley & Sons, Chichester 2007 Chapter 7 "Designs with more than two formulations" — Regards, Detlew |
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derya2626 ☆ Turkey, 2015-08-20 17:07 (3165 d 03:37 ago) @ d_labes Posting: # 15316 Views: 5,535 |
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❝ Hauschke, Steinijans, Pigeot ❝ Bioequivalence Studies in Drug Development ❝ Wiley & Sons, Chichester 2007 ❝ Chapter 7 "Designs with more than two formulations" Thank You, I know this book, but I could not find anything about confidence intervals, alpha-adjustment or ANOVA  Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Ohlbe] |
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Relaxation ★ Germany, 2015-09-01 14:04 (3153 d 06:41 ago) @ derya2626 Posting: # 15371 Views: 5,186 |
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Hello Derya and Hi to everybody. I would like to continue that discussion and adding my 2 cents here. My opinion has a good chance to be wrong, but then the corrections will be highly appreciated. ❝ There are 2 different dosages of the same test drug (T1, T2) and one dosage of reference (R). You mean dosage forms or different formulations, right? Like in two candidates for the new product ❝ -Should I compare "T1 vs R" and "T2 vs R" in 2 anova tables? From my understanding of the current thinking in the EU and because I personally do not understand why an ANOVA including also unrelated treatments should be beneficial at all I would not include that treatment not being compared. In other words, I would always prefer a pairwise comparison, so "Yes". ❝ -If I make 2 anova should I adjust the alpha? I think that is a great question. My safe answer would be "Yes" and I know of some colleagues that would support this, because this is a classical situation of testing multiple times/formulations and being happy with 1 positive result. At least when this is your pivotal study for submission. If it is "only" an exploratory pilot adjustment is of less relevance. ❝ -And if I adjust the alpha, does the CI change? ❝ Not 90% anymore...? Sure, it is 1-2*ALPHA However, my problem without an answer I understand would be: ALPHA-adjustment is requested in cases where I test multiple formulations in one study. However, nobody seems to expect that when I simply test multiple formulations in separate studies. Is there any rationale to not consider these studies (of which I even do not need to tell anybody as they do not concern "the new product") multiple testing? Best regards, Steven. |
Ing. Helmut Schütz