Bioequivalence and Bioavailability Forum

Sample Size Calculation [Software]

posted by d_labes  – Berlin, Germany, 2008-04-23 13:54 (5845 d 08:03 ago) – Posting: # 1793
Views: 28,787

Dear Sasikumar,

as always with "The power to know" nobody knows exactly what to code.
After fiddling a little bit with the new experimental (in SAS 9.1) PROC POWER I came up with the code

proc power;
  Pairedmeans
  test  = Equiv_ratio
  dist  = lognormal
  CV    = 0.05 0.075 0.1 0.125 0.15 0.175 0.2 0.225 0.25 0.275 0.3
  meanratio = 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2
  lower = 0.8
  upper = 1.25
  alpha = 0.05
  power = 0.8
  npairs= .
  corr  = 0.0
  ;
run;

With that code you can reproduce the block for power = 80% in
Diletti et.al., "Sample size determination for bioequivalence assessment ..."
Int. J. Clin. Pharm. Ther. Tox., Vol.30 Suppl. No.1, pp S51-58, 1992
Table 1 for multiplicative model.
With some minor deviations for CV=5% and 7.5%.

Note that the CV has to given as ratio, not percent.

Note further that uneven npairs have to rounded to even numbers to get a sequence balanced TR/RT design.

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 Calculationd_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 design yuvrajkatkar 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