Sundar.M
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India,
2018-09-27 09:11
(892 d 15:41 ago)

Posting: # 19330
Views: 2,277
 

 RSABE - Sequence [RSABE / ABEL]

Dear all,

What would be the advantages/disadvantages of following 6 sequences (TRR, RTR, RRT, RTT, TRT and TTR) in a RSABE design, instead of 3 sequences as per FDA recommendations. Your comments are highly appreciated.


Thanks
Sundar. M
Helmut
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Vienna, Austria,
2018-09-28 11:15
(891 d 13:37 ago)

@ Sundar.M
Posting: # 19337
Views: 1,904
 

 Suggested: TRT|RTR

Hi Sundar,

» […] advantages/disadvantages of following 6 sequences (TRR, RTR, RRT, RTT, TRT and TTR) in a RSABE design, instead of 3 sequences as per FDA recommendations.

Advantages
  • Additionally to the estimate of CVwR you get the one of CVwT (good to know esp. if your study is a pilot and you want to design a pivotal study where CVwR ≠ CVwT). In the partial replicate you have to assume that CVwR = CVwT.
  • If swR <0.294 (only ABE acceptable) no convergence issues in the mixed-effects model with the FDA’s covariance-specification.
Disadvantages
  • Sample size is a multiple of six (instead of three in the partial replicate and two in the three-period full replicate).
  • Design currently not implemented in PowerTOST’s function sampleN.RSABE().
If you want to kill two birds with one stone I recommend the three-period two-sequence full replicate design (TRT | RTR) instead.

Dif-tor heh smusma 🖖
Helmut Schütz
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Sundar.M
☆    

India,
2018-09-28 11:36
(891 d 13:16 ago)

@ Helmut
Posting: # 19338
Views: 1,837
 

 Suggested: TRT|RTR

Thank you HS!
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