Bioequivalence and Bioavailability Forum • BE study designs

BE study designs [Design Issues]

posted by Helmut – Vienna, Austria, 2006-01-17 10:27 (6666 d 16:22 ago) – Posting: # 56
Views: 25,203

❝ When you say that chance of regulatory acceptance of 3x3 is close to zero, you mean specifically for 3x3x3, or it is applicable to 3x3x6 design also?

You are right, I was not precise: 3×3×6 is acceptable, whereas 3×3×3 is not.

❝ Also, can you please let me know the reason for the same.

The 3×3×3 does not give us unbiased estimates.
Since we are interested in at least two pairwise comparisons (T₁ vs. R, T₂ vs. R), it is desirable to get estimates with the same degree of precision. However, to achieve this goal, the design must be balanced. A design is said to be balanced, if (acc. to Jones & Kenward):

Each formulation occurs only once with each subject.
Each formulation occurs the same number of times in each period.
The number of subjects who receive formulation i in some period followed by formulation j in the next period is the same for all i # j.

Williams' designs minimize the number of sequences for a given number of treatments and periods.
Unfortunately for three treatments your sample size has to be a multiple of six, which may be inconvenient in terms of practicability.

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Complete thread:

BE study designs Essar 2006-01-12 04:47
- BE study designs Helmut 2006-01-12 18:38
  - BE study designs Essar 2006-01-13 04:40
  - BE study designs Essar 2006-01-16 13:20
    - BE study designs Helmut 2006-01-16 15:39
      - BE study designs Essar 2006-01-17 04:53
        
        BE study designsHelmut 2006-01-17 09:27
      - BE study designs nguyenvo 2006-04-30 21:40
        
        sample size reference Helmut 2006-05-01 11:59
        BE study designs olacy 2006-06-23 09:28
        
        Reference (direct link) Helmut 2006-06-24 12:45
  - BE study designs shiv 2006-01-25 06:46
    - ANVISA?! Helmut 2006-01-25 13:37