Bioequivalence and Bioavailability Forum • LSM for unbalanced sequences -SAS-

LSM for unbalanced sequences -SAS- [Regulatives / Guidelines]

posted by yicaoting – NanKing, China, 2011-10-04 21:37 (4964 d 09:23 ago) – Posting: # 7423
Views: 14,512

Dear d_labes,
Thanks for your test of my SAS code.

Now, I can manually calculate LSM to obtain the same result of WinNonlin and SAS. But new problem arises.

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

Let's take my results for my unequal sequences data as example:

In WNL:
For original data, I get:

Treatment   LSM      SE    CI level T_critical LowerCI  UpperCI

1         235.1521 12.7463   90       1.727    213.1332 257.1711

2         231.8667 12.7463   90       1.727    209.8477 253.8856

For "Ln(x)" transformed data, I get:

Treatment   LSM      SE    CI level T_critical LowerCI  UpperCI

1           5.4356  0.0563   90       1.721     5.3387   5.5326

2           5.4266  0.0563   90       1.721     5.3296   5.5235

In SAS:
For original data, I get:

                                                                           H0:LSMean1=

                                  logAUC        Standard    H0:LSMEAN=0      LSMean2

             formulation          LSMEAN           Error       Pr > |t|       Pr > |t|

             1                235.152143        7.344914         <.0001         0.7564

             2                231.866667        7.344914         <.0001





                                           logAUC

                      formulation          LSMEAN      90% Confidence Limits

                      1                235.152143      222.215471   248.088815

                      2                231.866667      218.929995   244.803339

For "Ln(x)" transformed data, I get:

                                        Least Squares Means



                                                                           H0:LSMean1=

                                  logAUC        Standard    H0:LSMEAN=0      LSMean2

             formulation          LSMEAN           Error       Pr > |t|       Pr > |t|

             1                5.43564054      0.03630235         <.0001         0.8623

             2                5.42656860      0.03630235         <.0001





                                           logAUC

                      formulation          LSMEAN      90% Confidence Limits

                      1                  5.435641        5.371701     5.499580

                      2                  5.426569        5.362629     5.490508

It's really puzzled me, I am eagerly need help from d_labes, HS, yjlee168, ElMaestro or others who are expertised at this problem.

Give my greatest thanks to you.

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