Bioequivalence and Bioavailability Forum • Sequential designs (history and future)

Sequential designs (history and future) [Power / Sample Size]

posted by yjlee168 – Kaohsiung, Taiwan, 2010-03-29 21:19 (5525 d 18:05 ago) – Posting: # 4989
Views: 13,402

Dear Helmut and ElMaestro,

Thank you for your comments.

❝ Well, in Canada and Japan naïve pooling was acceptable for many years (in Canada for almost the last 20 years!). When the sample size turned out to be too small to demonstrate BE, additional subjects could be included - no

So in the case of sequential designs, when we get non BE results, the first thing is to check if the power is o.k. (defined as equal to or greater than 80%). If not, then we can go to Stage 2 by recruiting more subjects. According to Potvin D, et al., 2008, there seems only one chance (Method A-D). The authors considered Method C as the method of choice, and stated that Method B & C has been accepted by FDA (p. 259). If we like to add the sequential designs into bear, we have to implement the methods: to evaluate BE at Stage 1 (alpha = 0.0294) and to calculate sample size based on Stage 1 and alpha = 0.0294, and finally to evaluate BE at Stage 2 using data from both stages (alpha = 0.0294). The alpha level is not commonly used in statistics. However it seems feasible, I guess.

❝ correction of the alpha-level… Obviously the patient's risk may be >0.05, […]

❝ Sequential designs were never part of the official guidelines in the US and the EU. However, the introduction of Potvin's paper states that sequential design studies were accepted by the FDA in the past. The recent EU-GL allows for a sequential design; the actual method is not stated (but the description matches Potvin's).

Now I know why you said the sequential designs was your practice standard in the previous thread. Many thanks. I do learn a lots.

—
All the best,
-- Yung-jin Lee
bear v2.9.2:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here

Complete thread:

Sample Size BA/BE Sriraj 2010-02-26 14:32 [Power / Sample Size]
- Sample Size BA/BE Helmut 2010-03-01 14:00
  - Sample size for a pilot study to estimate the CVintra yjlee168 2010-03-01 19:25
    - Sample size for a pilot study to estimate the CVintra Helmut 2010-03-01 21:01
      - Sample size for a pilot study to estimate the CVintra yjlee168 2010-03-01 23:47
        
        Sample size for a pilot study to estimate the CVintra Helmut 2010-03-03 19:04
        
        Sample size for a pilot study to estimate the CVintra yjlee168 2010-03-04 22:35
      - 80% confidence ? d_labes 2010-03-19 13:02
        
        75% confidence... Helmut 2010-03-19 14:12
    - Sample size for a pilot study to estimate the CVintra ElMaestro 2010-03-01 22:23
      - Sample size for a pilot study to estimate the CVintra yjlee168 2010-03-02 00:02
      - Sample size for a pilot study to estimate the CVintra Helmut 2010-03-02 02:19
        
        Sample size for a pilot study to estimate the CVintra yjlee168 2010-03-29 13:27
        
        Sample size for a pilot study to estimate the CVintra ElMaestro 2010-03-29 13:39
        
        Sample size for a pilot study to estimate the CVintra yjlee168 2010-03-29 13:47
        
        Sequential designs (history and future) Helmut 2010-03-29 14:19
        
        Sequential designs (history and future)yjlee168 2010-03-29 19:19
        
        Sequential designs (history and future) Helmut 2010-03-29 20:43
        
        Sequential designs (history and future) yjlee168 2010-04-01 18:58
        
        Sequential designs (WinNonlin vs. bear) Helmut 2010-04-02 21:00