Bioequivalence and Bioavailability Forum • PASS simulator?

PASS simulator? [Design Issues]

posted by d_labes – Berlin, Germany, 2015-08-06 17:25 (3514 d 09:58 ago) – Posting: # 15188
Views: 12,010

Dear BE-proff,

❝ PASS simulator says ...

What is PASS simulator? What does it simulate?

IMHO for the question asked simulations are not the thing needed.
There is an analytic solution for the problem to calculate the power of a 2x2 crossover given the sample size, assumptions about the 'true' intra-subject CV and 'true' ratio T/R. It is described in the Diletti paper Balaga mentioned. That solution can be used to estimate the sample size.

BTW: I get using the R add-on package PowerTOST which uses the exact power formula based on Owen's Q:

library(PowerTOST)

sampleN.TOST(CV=0.15, targetpower=0.9, theta0=0.95)



+++++++++++ Equivalence test - TOST +++++++++++

            Sample size estimation

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

Study design:  2x2 crossover 

log-transformed data (multiplicative model)



alpha = 0.05, target power = 0.9

BE margins        = 0.8 ... 1.25 

Null (true) ratio = 0.95,  CV = 0.15



Sample size (total)

 n     power

16   0.926021

@Balaga:
There are some lectures/presentations given by Helmut on the topic 'Power/Sample size' which I highly recommend you.
Moreover there is an extra category in this forum 'Power / sample size' with numerous discussions for your question(s).

—
Regards,

Detlew

Complete thread:

Sample size justification bkrao 2015-08-06 09:12 [Design Issues]
- Sample size justification BE-proff 2015-08-06 14:19
  - PASS simulator?d_labes 2015-08-06 15:25
    - PASS simulator? BE-proff 2015-08-07 20:08
      - Owen’s Q | noncentral t | shifted central t Helmut 2015-08-08 02:32
        
        Owen’s Q | noncentral t | shifted central t BE-proff 2015-08-09 15:36
        
        PowerTOST crash-course Helmut 2015-08-09 16:40
        
        Owen’s Q | noncentral t | shifted central t - PASS? d_labes 2015-08-10 11:30
- Sample size justification Helmut 2015-08-07 01:21
  - Sample size justification bkrao 2015-08-07 06:06
    - Guesstimates Helmut 2015-08-07 13:53
      - Guesstimates bkrao 2015-08-08 06:03
        
        Guesstimates jag009 2015-08-10 20:08
        
        Guesstimates bkrao 2015-08-10 20:44