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ioanam ★ Romania, 2009-01-06 23:42 (6372 d 12:35 ago) Posting: # 3001 Views: 4,783 |
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Good evening and Happy New Year, I would like to receive an answer to my question. After a pilot bioequivalence study, I obtained an intraCV for Cmax of 34%. Sample size for the pivotal study obtained after statistical calculation was of 36 subjects. The sponsor representative showed me other calculus for this parameter using different software, obtaining a number of 48 subjects. Who is right in this case? Thank you very much, Jo -- Edit: Subject line changed. [Helmut] |
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Helmut ★★★   Vienna, Austria, 2009-01-07 00:48 (6372 d 11:29 ago) @ ioanam Posting: # 3002 Views: 3,872 |
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Dear Jo! ❝ [...] intraCV for Cmax of 34%. ❝ Sample size [...] after statistical calculation was of 36 subjects. ❝ The sponsor [...] showed [...] different software, obtaining [...] 48 subjects. ❝ Who is right in this case? For ±5% deviation of test from reference and 80% power using exact methods I'm getting 50 subjects (because the calculated sample size is slightly larger than 48 and must be rounded up to the next even number) according to the R code given in this post (with this modification; also implemented in package bear), in StudySize 2.0.1, and in FARTSSIE 1.6. Approximations (Hauschke et al. (1992), Chow & Wang (2001); references) come up with 50 subjects also. How did you get 36? I'm getting 36 for T/R=100% and 75% power. 100% is too optimistic, and 75% power leads to 25% producer's risk...  — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png) Helmut Schütz ![[image]](https://static.bebac.at/img/CC by.png) The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
Ing. Helmut Schütz