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atish_azad ☆ 2008-06-27 15:24 (5772 d 05:09 ago) Posting: # 1978 Views: 7,330 |
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Dear all, Kindly let me know whether we can have separate Variance in three way crossover study comparing two Test with one Reference (e.g T1 and T2 with R). When I used WinNonlin software for analysis I got combined variance for T1 T2 and R. I want Varince for T1 R and T2 R separatly is it possible. Kindly let me know. Regards, Atish |
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Helmut ★★★   Vienna, Austria, 2008-06-27 20:56 (5771 d 23:37 ago) @ atish_azad Posting: # 1979 Views: 6,588 |
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Dear Atish! ❝ When I used WinNonlin software for analysis I got combined variance for T1 ❝ T2 and R. Not only in WinNonlin. You are getting only the residual variance - which includes information from all sequences/periods/treatments/subjects... ❝ I want Varince for T1 R and T2 R separatly is it possible. Not from a three way study. If you have used a variance-balanced design (6 sequences) it should be possible to extract two 'pseudo-two-way studies' (see this post for an example), but I don't see the reason behind in your case. — 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 |
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atish_azad ☆ 2008-06-28 09:01 (5771 d 11:32 ago) @ Helmut Posting: # 1980 Views: 6,091 |
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Dear HS, This is a pilot three squence, three period crossover study. 1. Ratio for T2/R is around 98.63% and for T1/R is around 50.00%. I guess Variance is too high Which has affected 90% CI for T2/R to go out of Bioequivalence limit. 2. Calculated sample size for ratio T2/R and Using common variance is too high (more than 100). 3. When I did the analysis by blocking T1 from pharmacokinetic output of WinNonlin ratio of T2/R is around 105.00% and CI fall within bioequivalence limit and intraCV is around 27.99% (calculated from variance). 4. Calculated sample size for ratio T2/R and Using variance (intra CV of 27.99%) is around 33. 5. By blocking T1, ANOVA table shows two degree of freedom for Sequence and Period, since there are 3 Sequence and 3 Period. 6. Is my analysis by blocking T1 is correct? 7. Can I use sample size of 36 if a pivotal study is planned for T2 and R? Regards, Atish |
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Ohlbe ★★★ France, 2008-06-28 16:32 (5771 d 04:01 ago) @ atish_azad Posting: # 1982 Views: 6,444 |
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Dear Atish, ❝ intraCV is around 27.99%  How many subjects did you have in your study to be able to determine intraCV with such a precision ? Have a look at this message. From a pilot study, poorly designed (3-sequence, not 6), "around 28 %" or even "around 30%" would be sufficient... Regards Ohlbe |
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atish_azad ☆ 2008-06-29 12:01 (5770 d 08:32 ago) @ Ohlbe Posting: # 1985 Views: 6,498 |
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Dear Ohlbe, The study was done on 15 subject and one was dropped from satistical analysis. Regards Atish |
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Jaime_R ★★ Barcelona, 2008-07-11 23:41 (5757 d 20:52 ago) @ atish_azad Posting: # 2017 Views: 5,917 |
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Dear Atish! ❝ [...] one was dropped from satistical analysis. ^^^^^^^Sometimes a typo tells more than a thousand words...  — Regards, Jaime |
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atish_azad ☆ 2008-07-12 20:37 (5756 d 23:56 ago) @ Jaime_R Posting: # 2019 Views: 6,456 |
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Dear Jaime_R/all, I am sorry for the spelling mistake. Regards, Atish |
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Jaime_R ★★ Barcelona, 2008-07-14 18:05 (5755 d 02:28 ago) @ atish_azad Posting: # 2027 Views: 6,343 |
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Dear Atish! ❝ I am sorry for the spelling mistake. No need for excuses; it only sounded that funny - and it's a typing error I'm used to make myself (unconciously?!). — Regards, Jaime |
Ing. Helmut Schütz