Bioequivalence and Bioavailability Forum • Lack of ISR / only 5% ISR in study with 656 samples

Lack of ISR / only 5% ISR in study with 656 samples [Regulatives / Guidelines]

posted by ElMaestro – Denmark, 2013-04-24 01:31 (4420 d 18:20 ago) – Posting: # 10480
Views: 14,592

Cool code Helmut.

Run your code, then do shapiro.test(data) and discuss if the high p-value proves that the data are Gaussian.
Next do this:


data   <- c(-1.05,  -6.38, -5.30,  -5.55,  -2.99,  -2.24, +10.75, +0.90,

            -6.66,  -5.01, -2.74, -10.98,  +4.43,  -3.53,  -8.85, -7.38,

            -8.35, +11.13, -4.07, -15.58,  +2.05, -14.86,  -3.34, +2.66,

            -6.80,  +5.60, -2.48,  +5.61, -11.71, +10.61,  -4.00, -1.73)

                            # Observed deviations

size   <- 656               # No. of samples in a study

ifelse(size < 1000,         # EMA: 10% if <1000; +5% for >1000

  ISR.no <- ceiling(size*0.1),

  ISR.no <- 100 + ceiling((size-1000)*0.05))

sims   <- 1e6               # No. of simulated studies

failed <- 0                 # ISR failed criterion (≤1/3 of repeats >20% dev.)

for (i in 1:sims) {

  xboot = sample(data, replace=T)

  y      <- length(xboot[abs(xboot)>20]) # No. of abs. deviations > 20%

  y      <- y/ISR.no        # Fraction of repeats with > 20% deviation

  if (y > 1/3) failed <- failed + 1

}

cat(sprintf("%i",sims),"simulated studies with", size, "samples:\n",

  "Method: Bootstrapping (Mersenne-Twister) of ISR data\n",

  "Failed criterion (deviations >20% in >1/3 of repeats) seen in",

  sprintf("%.2f%% %s", 100*failed, "of studies.\n"))

...and argue that even when you do not make any assumption of ISR distribution you are still very clearly very far from any sort of trouble.

—
Pass or fail!
ElMaestro

Complete thread:

Incurred sample reanalysis sarada06884 2013-04-09 12:22 [Regulatives / Guidelines]
- Incurred sample reanalysis Ohlbe 2013-04-09 14:09
  - Incurred sample reanalysis The Outlaw Torn 2013-04-10 08:40
    - Clopidogrel Ohlbe 2013-04-10 10:34
      - Clopidogrel The Outlaw Torn 2013-04-10 11:31
        
        Lack of ISR / only 5% ISR in study with 656 samples Helmut 2013-04-22 17:01
        
        Lack of ISR / only 5% ISR in study with 656 samples ElMaestro 2013-04-22 18:56
        
        Lack of ISR / only 5% ISR in study with 656 samples Helmut 2013-04-22 19:35
        
        "Meth" - apologies ElMaestro 2013-04-22 20:03
        
        "Meth" - apologies The Outlaw Torn 2013-04-23 08:27
        
        "Meth" - apologies ElMaestro 2013-04-23 14:29
        
        "ISR" - apologies The Outlaw Torn 2013-04-24 07:44
        
        Repeat use ElMaestro 2013-04-24 11:08
        
        Repeat use Ohlbe 2013-04-24 11:41
        
        Repeat use ElMaestro 2013-04-24 13:45
        
        "ISR" – resolved Helmut 2013-09-20 21:50
        
        "ISR" – resolved Dr_Dan 2013-09-22 16:56
        
        Lack of ISR / only 5% ISR in study with 656 samplesElMaestro 2013-04-23 23:31
        
        Some more stuff Helmut 2013-04-24 02:08
        Lack of ISR / only 5% ISR in study with 656 samples nobody 2014-10-23 10:06