Bioequivalence and Bioavailability Forum

Non-informative “profiles” [General Sta­tis­tics]

posted by Helmut  – Vienna, Austria, 2014-03-11 15:04 (4027 d 11:41 ago) – Posting: # 12597
Views: 10,296

Hi Ohlbe,

❝ […] If that's for the test formulation, I somewhat disagree... If you have a formulation that gives you no, or just one or two, concentration above the LLOQ, that's relevant information. I have no idea how these should be analysed, but just dropping them from the analysis is not an idea I'm comfortable with.

Fabrice stated that this was not a BE study. I think we need more information. The BE-GL talks about exclusion (in exceptional cases) if plasma concentrations are low after the reference product. But in the Q&A document’s section about gastric-resistant formulations we read:

Therefore, but only under the conditions that sampling times are designed to identify very delayed absorption and that the incidence of this outlier behaviour is observed with a comparable frequency in both, test and reference products, these incomplete profiles can be excluded from statistical analysis provided that it has been considered in the study protocol.

– which leads to the open question what a “comparable frequency” is. Last year in Bonn I pre­sented an example of four low profiles after one treatment and zero after the other in study in 24 subjects. Statistically the frequencies are not significantly different (5/0 would be with p 0496). Members of the PKWP unambiguously expressed their opinion that they don’t like that.

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


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Complete thread:

• Log-transformation of "null" PK para­meters fno 2014-03-11 12:18 [General Sta­tis­tics] 
  • Non-informative “profiles” Helmut 2014-03-11 13:29
    • Non-informative “profiles” Ohlbe 2014-03-11 13:47
      • Non-informative “profiles”Helmut 2014-03-11 14:04
        • Non-informative “profiles” fno 2014-03-11 15:52
          • Non-informative “profiles” Helmut 2014-03-11 17:22
            • Non-informative “profiles” ElMaestro 2014-03-11 18:50
              • OT: log(0) - NaN, NA or what d_labes 2014-03-12 08:59
                • OT: log(0) - NaN, NA, ‘.’, –∞, or empty Helmut 2014-03-12 15:31
              • Non-informative “profiles” fno 2014-03-12 11:18
                • Non-informative “profiles” nobody 2014-03-12 13:18