Bioequivalence and Bioavailability Forum

Deep shit [RSABE / ABEL]

posted by Mikalai  – Belarus, 2020-01-31 16:07  – Posting: # 21121
Views: 4,127

Dear Helmut

» Duno what you mean. Are you considering the sample size of a 2×2×2 crossover? The sample size of the 2-period 4-sequence full replicate is ~½ though the number of treatments / biosamples (driving the study cost) are essentially the same.
» CV (%) ABE.2x2x2 ABE.2x2x4 n.ABEL n.ABEL.Bonf n.ABEL.adj n.Molins
»     20        20        10     18          24         18       22
»     30        40        20     34          44         42       42
»     40        66        34     30          38         32       36
»     50        98        50     28          34         28       32
» Try the functions pa.ABE() and pa.scABE() of PowerTOST.

» The plots in the slide are all for ABEL. A comparison of ABE and the EMA’s (unadjusted) ABEL:
»
»
»
» At 30% sample sizes are 40 and 34, at 40% 68 and 30.
»
» Hhm, not sure what you mean.

I just would like to say that it has no sense to conduct ABEL/RABE trials if the CV is assumed around 30% because, in order to control TIE, we have to increase the sample size to around that of usual ABE trials. It violates GCP principles in this case and invalidates the ABEL/RABE approach (subjects are subjected to unnecessary risks in the ABEL/RABE trials). And it very complicates the matter. Basically, when should we consider an ABEL/RABE trial?

Best regards

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It also seems that when we wish to control TIE the sample size will be around 50 (worst scenario + dropout rate) in almost every case (usually little known about reference withindividual variability) of the ABEL/RABE. But I have rarely seen such trials.

Regards

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Edit: Merged with a later (now deleted) post. You can edit your posts for 24 hours. [Helmut]

Complete thread:

• Statistical evaluation and BE hypo­theses in full replicate design Elena777 2020-01-28 07:02 [RSABE / ABEL] 
  • Inflation of the TIE as well Helmut 2020-01-29 15:38
    • Inflation of the TIE as well Elena777 2020-01-29 20:01
      • Tricky… Helmut 2020-01-30 12:07
        • Tricky… Mikalai 2020-01-30 13:08
          • Terrible… Helmut 2020-01-30 15:09
            • Tricky… Mikalai 2020-01-30 16:02
              • Deep shit Helmut 2020-01-30 16:59
                • Deep shit Mikalai 2020-01-30 18:39
                  • Deep shit Mikalai 2020-01-30 19:31
                  • Deep shit Helmut 2020-01-30 20:07
                    • Deep shit Mikalai 2020-01-31 11:14
                      • Deep shit Helmut 2020-01-31 14:00
                        • Deep shitMikalai 2020-01-31 16:07
          • Flawed evaluation accepted Helmut 2020-01-31 12:19
            • Flawed evaluation accepted Mikalai 2020-01-31 12:40
              • Flawed evaluation accepted Helmut 2020-01-31 14:17
                • Flawed evaluation accepted Mikalai 2020-01-31 16:41
                  • Flawed approach even if accepted 😡 Helmut 2020-01-31 20:28
                    • Flawed approach even if accepted 😡 Mikalai 2020-02-01 16:18
                      • misunderstanding mittyri 2020-02-01 21:34
                        • misunderstanding Mikalai 2020-02-06 13:41
                          • misunderstanding mittyri 2020-02-06 16:23
                      • The globe is flat! d_labes 2020-02-05 19:16
        • Tricky… wienui 2020-01-30 18:53
          • Tricky… Helmut 2020-01-30 19:18
            • Tricky… wienui 2020-02-03 07:10
              • ABE vs. ABEL Helmut 2020-02-03 12:25
                • zigzag d_labes 2020-02-05 18:53
                  • zigzag Helmut 2020-02-05 19:46
                    • zigzag Mikalai 2020-02-06 11:38
                      • helter-skelter Helmut 2020-02-06 20:12
                        • helter-skelter Mikalai 2020-02-10 16:10
    • Inflation of the TIE as well zizou 2020-02-01 17:00
      • Inflation of the TIE as well nobody 2020-02-01 23:30
  • Statistical evaluation and BE hypo­theses in full replicate design nobody 2020-02-03 15:07