Bioequivalence and Bioavailability Forum • R1 vs R2

R1 vs R2 [RSABE / ABEL]

posted by ElMaestro – Denmark, 2012-10-11 14:09 (4598 d 10:03 ago) – Posting: # 9387
Views: 10,939

Dear d_labes,

❝ To repeat my question: Which result do you trust?

❝

❝ What bothers me further is that a distinction of R into R1 and R2 is purely arbitrary. An ratio R vs. R different from 1 is horrible for me.

Yes, this is truly weird.
We are testing one and the same product against itself, so by definition we know that the true P/E is exactly 1 with 100% confidence. In practice we get some variability, though, if we try and verify it in practice. Biology sucks.

❝ Moreover the distinction of R into R1 and R2 and evaluation of the R data alone via ANOVA with effects tmt2, period, sequence and subject within sequence is not universally valid. Try it with the EMA dataset I, a 4 period full replicate study. I got:

❝ Source DF Type III SS Mean Square F Value Pr > F

❝


❝   tmt2                  0      0.0000000       .              .      .

❝   sequence              0      0.0000000       .              .      .

❝   subject(sequence)    74    118.3549864      1.5993917      8.02   <.0001

❝   period                1      0.3995422      0.3995422      2.00   0.1612

❝ Trapped in the type III hell! No estimate of R1 vs R2 obtainable.

❝ It only functions if you omit period from the model.

Can you send me the dataset (coded R1 and R2) in an excel file or something like that? I need to look at the columns and rank of the design matrix to figure it out.

Muchas gracias.

—
Pass or fail!
ElMaestro

Complete thread:

Ref. vs. Ref. in partial replicate design d_labes 2012-04-25 15:52
- Ref. vs. Ref. in partial replicate design again d_labes 2012-10-10 10:56
- Ref. vs. Ref. in partial replicate design ElMaestro 2012-10-10 12:39
  - Ref. vs. Ref. in partial replicate design d_labes 2012-10-10 16:26
    - Ref. vs. Ref. in partial replicate design ElMaestro 2012-10-10 17:16
      - R vs. R in partial replicate design d_labes 2012-10-11 09:43
        
        R1 vs R2 ElMaestro 2012-10-11 10:26
        
        R1 vs R2 d_labes 2012-10-11 12:01
        
        R1 vs R2ElMaestro 2012-10-11 12:09
        
        R1 vs R2 d_labes 2012-10-11 12:46
        
        treatment df ElMaestro 2012-10-11 13:38
        
        Missunderstanding d_labes 2012-10-11 16:34
        
        Missunderstanding, crippled ElMaestro 2012-10-11 18:12
        
        EMA crippled method - R peculiarities d_labes 2012-10-12 14:54
        
        All is good, just forget ANOVA - you don't need it! ElMaestro 2012-10-12 16:25
        
        Just forget ANOVA. What next? d_labes 2012-10-15 08:35
        
        Just forget ANOVA. What next? ElMaestro 2012-10-15 10:04