atish_azad ☆ 20080627 15:24 (5572 d 02:40 ago) Posting: # 1978 Views: 7,011 

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 
Helmut ★★★ Vienna, Austria, 20080627 20:56 (5571 d 21:08 ago) @ atish_azad Posting: # 1979 Views: 6,344 

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 variancebalanced design (6 sequences) it should be possible to extract two 'pseudotwoway studies' (see this post for an example), but I don't see the reason behind in your case. — Diftor heh smusma 🖖🏼 Довге життя Україна! _{} Helmut Schütz The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes 
atish_azad ☆ 20080628 09:01 (5571 d 09:03 ago) @ Helmut Posting: # 1980 Views: 5,845 

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 
Ohlbe ★★★ France, 20080628 16:32 (5571 d 01:31 ago) @ atish_azad Posting: # 1982 Views: 6,197 

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 (3sequence, not 6), "around 28 %" or even "around 30%" would be sufficient... Regards Ohlbe 
atish_azad ☆ 20080629 12:01 (5570 d 06:02 ago) @ Ohlbe Posting: # 1985 Views: 6,257 

Dear Ohlbe, The study was done on 15 subject and one was dropped from satistical analysis. Regards Atish 
Jaime_R ★★ Barcelona, 20080711 23:41 (5557 d 18:22 ago) @ atish_azad Posting: # 2017 Views: 5,671 

Dear Atish! ❝ [...] one was dropped from satistical analysis. ^^^^^^^ Sometimes a typo tells more than a thousand words... — Regards, Jaime 
atish_azad ☆ 20080712 20:37 (5556 d 21:26 ago) @ Jaime_R Posting: # 2019 Views: 6,212 

Dear Jaime_R/all, I am sorry for the spelling mistake. Regards, Atish 
Jaime_R ★★ Barcelona, 20080714 18:05 (5554 d 23:59 ago) @ atish_azad Posting: # 2027 Views: 6,100 

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 