Geometric means ± SD [🇷 for BE/BA]

posted by Helmut Homepage – Vienna, Austria, 2016-01-27 14:51 (3300 d 14:56 ago) – Posting: # 15866
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Hi ElMaestro & Lizhao,

❝ ❝ If I want to plot a mean plot (mean and error bars) of a crossover biequivalence study, should I use within-subject confidence intervals or between-subject confidence intervals?


❝ I think you can plot those curves in any way you want? The BE decision is taken on basis of the CI's.

❝ If you plot Conc versus time and average across subjects then you would often choose to use between-subject variances for error bars.


Between – yes. (m/V)2? Ahem…
I suggest to plot geometric means* ± backtransformed standard deviations. Concentrations likely follow a log-normal distribution. Arithmetic means ± SD can lead to bizarre plots (like this one published by the FDA, page 12 of the PDF).



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