Bioequivalence and Bioavailability Forum • LS Means mean?

LS Means mean? [Regulatives / Guidelines]

posted by d_labes – Berlin, Germany, 2011-10-05 14:45 (4963 d 15:08 ago) – Posting: # 7426
Views: 14,362

Dear yicaoting!

❝ Both WNL and SAS give us the same SE for R and T, why?

I as a bloody statistical layperson can't explain with understandable words what LSMeans really are. Try to :google:

'standard error least square means' OR 'lsmeans standard error' and hope to find an explanation which satisfies you.
I myself have accepted this as a fact within the 2x2 crossover design evaluation without really understanding the 'Why'.
Since the term 'Least square mean' is ascribed to this is a hornets' nest similar to the 'Type III Sum of squares'.

❝ The SE and 90%CI for R and T are not equal within WNL and SAS, which will be reliable? (Even for equal sequences data)

Wow! That's curious.
But it does not matter too much because we are not interested in the LSMeans itself but in the treatment difference (in the log-transformed domain) and the 90% CI for that.
As long as these results are identical all is right with the world I think :cool:

—
Regards,

Detlew

Complete thread:

Least Square Means (LSM) for unequal sequence yicaoting 2011-10-03 14:37 [Regulatives / Guidelines]
- Least Square Means (LSM) for unequal sequence ElMaestro 2011-10-03 14:51
  - Least Square Means (LSM) for unequal sequence yicaoting 2011-10-03 15:28
    - Least Square Means (LSM) for unequal sequence ElMaestro 2011-10-03 15:36
    - Least Square Means (LSM) for unequal sequence Helmut 2011-10-03 16:14
      - Least Square Means (LSM) for unequal sequence ElMaestro 2011-10-03 20:10
  - Least Square Means (LSM) for unequal sequence Pankaj Bhangale 2011-10-04 14:52
    - Weighted Means? Helmut 2011-10-05 01:53
- LSM for unbalanced sequences -SAS- d_labes 2011-10-04 09:39
  - LSM for unbalanced sequences -SAS- yicaoting 2011-10-04 19:37
    - SE for unbalanced sequences SAS vs. WinNonlin Helmut 2011-10-05 01:01
    - LS Means mean?d_labes 2011-10-05 12:45
      - LS Means mean? ElMaestro 2011-10-05 13:23
      - PHX/WNL vs. SAS Helmut 2011-10-08 02:21
        
        PHX/WNL vs. SAS Proc Mixed d_labes 2011-10-10 15:46
        
        PHX/WNL vs. SAS Proc Mixed Helmut 2011-10-10 16:30
        
        PHX/WNL vs. SAS Proc Mixed ElMaestro 2011-10-10 19:53
        
        Real mixed effects in WNL, SAS, GLM or Mixed (1) yicaoting 2011-10-13 18:39
        Real mixed effects in WNL, SAS, GLM or Mixed (2) yicaoting 2011-10-13 18:52
        Real mixed effects in WNL, SAS, GLM or Mixed (3) yicaoting 2011-10-13 19:05
        
        Must admit I am lost ElMaestro 2011-10-14 00:02
        
        Must admit I am lost yicaoting 2011-10-14 06:30
        
        Must admit I am lost - edited ElMaestro 2011-10-14 13:23