Bioequivalence and Bioavailability Forum • The secret of WinNonlin's BE's post-hoc Power analysis

The secret of WinNonlin's BE's post-hoc Power analysis [Software]

posted by yicaoting – NanKing, China, 2011-11-08 15:55 (4546 d 07:25 ago) – Posting: # 7637
Views: 8,813

go on validating WNL's and my formula using unbalanced data

Chow and Liu's famous data, delete Subject # 23 and 24's data both in period 1 and period 2.

For original data-----------------

WNL's result is

    Power of ANOVA for Confidence Level 90.00

    Power at 20% = 0.99266427

My result is

Power Analysis   

-----------------------------------------------------------------------------

Parameter   T stat 1     T stat 2     P value 1     P value 2     Power

-----------------------------------------------------------------------------

AUC       -2.671468902  -6.120905388  0.007332086  2.78018E-06   0.992670694

-----------------------------------------------------------------------------

For ln-transformed data----------
WNL's result is

    Power of ANOVA for Confidence Level 90.00

    Power at 20% = 0.97882724

My result is

Power Analysis   

-----------------------------------------------------------------------------

Parameter   T stat 1     T stat 2     P value 1     P value 2     Power

-----------------------------------------------------------------------------

ln(AUC)   -2.168810573  -5.618247059  0.02116397   8.44382E-06   0.978844474

-----------------------------------------------------------------------------

also same at level of 0.0001. Seems my formula works as WNL's inside hiden formula.

The level of the precision is interestingly same to that of BE's 90% CI.

go on validating WNL's and my formula using full data

Original data, use 93% CI, 20% diff to detect

WNL's power = 0.99020906

My power    = 0.990218894



Original data, use 93% CI, 13% diff to detect

WNL's power = 0.82872712

My power    = 0.828839088



Ln-transed data, use 93% CI, 20% diff to detect

WNL's power = 0.97637515

My power    = 0.976397234



Ln-transed data, use 93% CI, 13% diff to detect

WNL's power = 0.72133308

My power    = 0.721483927

All the results are satisfactory. Seems I have touched into WNL's black box.

Edit: Merged two posts. [Helmut]

Complete thread:

The secret of WinNonlin's BE's post-hoc Power analysis yicaoting 2011-11-08 14:40 [Software]
- The secret of WinNonlin's BE's post-hoc Power analysisyicaoting 2011-11-08 14:55
- The secret of WinNonlin's BE's post-hoc Power analysis Helmut 2011-11-08 15:06
- Power of superiority d_labes 2011-11-10 09:49
  - Power of superiority Helmut 2011-11-10 14:39
    - Power of equality d_labes 2011-11-10 16:42
      - Power of equality Helmut 2011-11-10 17:00
        
        Power of equality test - 2nd try for the logs d_labes 2011-11-11 09:55
        
        Crtl-C/Ctrl-V Helmut 2011-11-11 14:39
      - Power of equality yicaoting 2011-11-12 07:05