Bioequivalence and Bioavailability Forum • sample size for parallel design

sample size for parallel design [Software]

posted by yuvrajkatkar – Pune, Maharashtra (India), 2009-10-03 09:44 (5737 d 16:29 ago) – Posting: # 4289
Views: 28,594

Dear Sir,

Thanks a lot, Sir.

Ok Please see the Chow and Liu Sample size formula for parallel design

Suppose CV=.15
Assume n=32


n            32         32         32

alpha        0.05       0.05       0.05

beta         0.2        0.2        0.2

power        0.8        0.8        0.8

Theta        0.95       1          1.05

LN(Theta)2  -0.10259    0          0.09758

CV           0.15       0.15       0.15

CV^2         0.0225     0.0225     0.0225

talpha,2n-2  1.998971   1.998971   1.998971

tbeta,2n-2   1.669804   1.669804   1.669804



       2CV^2 (talpha,2n-2+tbeta/2, 2n-2)^2

  n >= -----------------------------------

                 0.2-|Theta|^2

Using this formula, I have got n= 2.001728, 3.028481, 5.913866

and using the below SAS code

proc power;

  Pairedmeans 

  test  = Equiv_ratio 

  dist  = lognormal

  CV    = 0.15

  meanratio = 0.95 1 1.05

  lower = 0.8

  upper = 1.25

  alpha = 0.05

  power = 0.8

  npairs= .

  corr  = 0.0

  ;

run;

I have got n= 12, 10, 11 per group
It means n=24, 20, 22 for parallel design

Which one is the right answer?

Edit: Reformated using BBCode (code); tabs substituted by blanks. Please see the Policy. [Helmut]

—
Best Regards,
Yuvraj

Complete thread:

Sample Size Calculation sasikumar 2008-04-03 09:19 [Software]
- Sample Size Calculation (SAS) Jaime_R 2008-04-03 13:13
- Sample Size Calculation d_labes 2008-04-23 11:54
  - Sample Size Calculation balakotu 2009-09-07 07:51
  - Sample Size Calculation yuvrajkatkar 2009-09-19 09:24
    - Paper, pencil, brain ;-) Helmut 2009-09-19 11:48
      - Paper, pencil, brain ;-) yuvrajkatkar 2009-09-21 15:10
        
        Paper, pencil, brain ;-) Helmut 2009-09-21 15:23
        Paper, pencil, brain ;-) Helmut 2009-09-21 18:33
        
        Paper, pencil, brain ;-) yuvrajkatkar 2009-09-22 16:09
        
        No paper, pencil, brain :-( Helmut 2009-09-22 18:22
        
        about your lectures yuvrajkatkar 2009-09-23 07:27
        
        About Trust Helmut 2009-09-23 13:50
        
        sample size calculation yuvrajkatkar 2009-10-01 13:33
        
        inter- / intra- / total variance Helmut 2009-10-01 13:52
        
        inter- / intra- / total variance yuvrajkatkar 2009-10-01 17:13
        
        Theta?! Helmut 2009-10-01 17:30
        
        sample size for parallel designyuvrajkatkar 2009-10-03 07:44
        
        Reference? Helmut 2009-10-03 13:46
        
        MSE obtain from Parallel study in WinNonlin yuvrajkatkar 2009-10-09 16:46
        
        Parallel study in WinNonlin Helmut 2009-10-10 10:51