Bioequivalence and Bioavailability Forum

Proposed changes [Two-Stage / GS Designs]

posted by Helmut  – Vienna, Austria, 2020-02-17 15:16 (1523 d 13:34 ago) – Posting: # 21178
Views: 5,896

Hi Mauricio,

❝ Instead of: "Type I error must be preserved and adjusted, and to demonstrate bioequivalence the level of confidence is 94.12%;"

❝

❝ I will only propose that: It must be demonstrated that the type I error of the study is controlled.

OK in principle. It’s always a good idea not only to propose a change but give a justification. Maybe refer to the EMA’s and the WHO’s guidelines stating that the adjusted α has to be specified in the protocol and the choice is at the company’s discretion. α 0.0294 (i.e., the 94.12% CI) is definitely not the only possible one.

❝ Instead of: "This second group must have at least 50% of the previous group"

❝

❝ I will propose that: The number of participants in the second stage must be calculated based on the data extracted from the first stage. The calculation must be justified considering possible losses and / or dropouts observed in the first stage.

OK. Do me a favor: Use estimated/estimation instead of calculated/calculation.
Of course, n₂ is always based on the eligible subjects in the interim (n₁), not on the subjects randomized.
Justification: A minimum stage 2 sample size is not covered by the published methods; any minimum n₂ might inflate the Type I Error. If that sounds too statistical write “the patient’s risk” instead.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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Complete thread:

• ANVISA guidelines for two-stage design Mauricio Sampaio 2020-02-11 20:52 [Two-Stage / GS Designs] 
  • Brainless copy-and-paste-devil Helmut 2020-02-12 02:26
    • Brainless copy-and-paste-devil Mauricio Sampaio 2020-02-12 17:33
  • ANVISA guidelines for two-stage design ElMaestro 2020-02-12 08:27
    • ANVISA guidelines for two-stage design nobody 2020-02-12 08:49
    • ANVISA guidelines for two-stage design Helmut 2020-02-12 13:12
    • ANVISA guidelines for two-stage design Mauricio Sampaio 2020-02-12 17:04
    • ANVISA guidelines for two-stage design Mauricio Sampaio 2020-02-12 17:11
  • ANVISA guidelines for two-stage design ElMaestro 2020-02-12 21:54
    • crap Helmut 2020-02-15 17:53
      • crap Mauricio Sampaio 2020-02-16 05:01
        • crap Helmut 2020-02-16 15:43
          • crap d_labes 2020-02-16 19:34
            • Explained crap remains crap Helmut 2020-02-17 12:49
              • Proposed changes Mauricio Sampaio 2020-02-17 13:50
                • Proposed changesHelmut 2020-02-17 14:16