Bioequivalence and Bioavailability Forum • Tutorial

Tutorial [Power / Sample Size]

posted by Alyssa – Malaysia, 2020-05-08 08:48 (1442 d 11:01 ago) – Posting: # 21406
Views: 7,491

Dear Helmut,

Thanks for the detailed tutorial!

I was trying to follow your command and out in the powerTOST, however, i cant get the sample size estimation. May i know what has gone wrong? Thank you ~

 # partial replicate, 3- and 4-period full replicate designs

> designs <- c("2x3x3", "2x2x3", "2x2x4")

> # desired powers

> target  <- c(0.80, 0.85, 0.90)

> # assign a data.frame of results

> res     <- data.frame(design = rep(designs, each = length(target)),

+                       target = target, n = NA, power = NA)

> # loop over the rows, apply the defaults:

> # T/R-ratio 0.90, 100,000 simulated studies

> for (j in 1:nrow(res)) {

+   res[j, 3:4] <- sampleN.scABEL(CV = CV, design = res$design[j],

+                                 targetpower = res$target[j],

+                                 print = FALSE, details = FALSE)[8:9]
+ }

Error in sampleN.scABEL(CV = CV, design = res$design[j], targetpower = res$target[j],  : 

  could not find function "sampleN.scABEL"

> print(res, row.names = FALSE)

 design target  n power

  2x3x3   0.80 NA    NA

  2x3x3   0.85 NA    NA

  2x3x3   0.90 NA    NA

  2x2x3   0.80 NA    NA

  2x2x3   0.85 NA    NA

  2x2x3   0.90 NA    NA

  2x2x4   0.80 NA    NA

  2x2x4   0.85 NA    NA

  2x2x4   0.90 NA    NA

Edit: Code and results BBCoded; see also this post #10. [Helmut]

Complete thread:

Sample size calculation (Pilot study result vs literature) Alyssa 2020-05-04 04:35
- Sample size calculation (Pilot study result vs literature) Dr_Dan 2020-05-04 08:46
  - Sample size calculation (Pilot study result vs literature) Alyssa 2020-05-04 09:26
- Estimation of CVw and/or CVwR Helmut 2020-05-04 12:07
  - Estimation of CVw and/or CVwR ElMaestro 2020-05-04 12:14
    - Mea culpa! Helmut 2020-05-04 12:40
      - It must be Myco ElMaestro 2020-05-04 13:46
        
        It is, it is! Helmut 2020-05-04 14:07
        
        It is.... Alyssa 2020-05-05 05:00
        
        Tutorial Helmut 2020-05-05 12:45
        
        TutorialAlyssa 2020-05-08 06:48
        
        library d_labes 2020-05-08 11:16
        Tutorial (from the start) Helmut 2020-05-08 13:08
        
        Tutorial (from the start) Alyssa 2020-05-12 04:05
        
        Tracking down error Helmut 2020-05-12 11:49
        
        Tracking down error: stringsAsFactors d_labes 2020-05-13 11:34
        
        R <4.0.0 Helmut 2020-05-13 12:07
        
        R <4.0.0 ElMaestro 2020-05-13 14:18
        
        R <4.0.0? Helmut 2020-05-13 14:21
        
        PowerTOST’s functions with as.character(design) d_labes 2020-05-13 18:50
        
        PowerTOST’s functions with as.character(design) Helmut 2020-05-13 18:55
        
        Tracking down error Alyssa 2020-05-15 05:08
        
        All’s well that ends well. Helmut 2020-05-15 10:52