Bioequivalence and Bioavailability Forum • Least Square Means (LSM) for unequal sequence

Least Square Means (LSM) for unequal sequence [Regulatives / Guidelines]

posted by yicaoting – NanKing, China, 2011-10-03 17:28 (5381 d 09:47 ago) – Posting: # 7412
Views: 16,811

Dear ElMaestro,

❝ 1. You take the Mean of T in Seq TR and the mean of T in Seq RT. You add them and divide by two. Do the same for R.

Thank you for your guide, your equation works well to calculate LSM for unequal sequences data (both for original and Ln-transformed data), thank you again.
But how to calculate SE in WinNonlin? The same SEs for R and T, why?

❝ 2. The crucial variability for a 2,2,2-BE design from which the 90% CI is derived is the residual sigma (which is your [pseudo-]within variability). Since there is no true replication of neither T nor R you cannot derive a within-subject variability separately for T or R. Think of it in matrix terms: Your error matrix is just a bunch of zeros and with the common sigma on the diagonal.

Thank you for your explanation on residual sigma.

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 sequenceyicaoting 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