Bioequivalence and Bioavailability Forum

❝ ❝ Sample size: 18

❝ ❝ Runtime (seconds):

❝ ❝ user system elapsed

❝ ❝ 0.14 0.01 0.15

❝

❝ I run the codes three times under R v4.0.3 and got:

❝

❝ Runtime (seconds):

❝    user  system elapsed

❝    0.11    0.00    0.13

❝    0.09    0.01    0.10

❝    0.11    0.00    0.11

❝

❝ a little bit faster. I guess that you have not upgraded to R 4.0.3 yet.

❝ R v4.0.3 is simply faster (still my gut feeling ).

❝ I remember that your Xeon computer runs faster than my Windows, even than my Linux notebook last time. Is it the same computer?

❝ ❝ BTW, in v2.5 of last Tuesday Dave removed all reference-scaled methods and gives the code of PowerTOST in a box.

❝

❝ Thanks for the information.

library(PowerTOST)
CV     <- seq(0.25, 0.65, 0.05)
theta0 <- 0.90
power  <- 0.80
design <- "2x2x4"
pers   <- as.numeric(substr(design, 5, 5))
n      <- data.frame(CV = CV)
theta1 <- numeric()
for (j in seq_along(CV)) {
  theta1[j] <- exp(-0.76*CV2se(CV[j]))
  if (CV[j] <= 0.3) theta1[j] <- 0.8
  if (CV[j] >= 0.5) theta1[j] <- exp(-0.76*CV2se(0.5))
  n.2x2x2       <- sampleN.TOST(CV = CV[j], design = "2x2x2",
                                targetpower = power, theta0 = theta0,
                                theta1 = theta1[j], theta2 = 1/theta1[j],
                                method = "nct", details = FALSE,
                                print = FALSE)[["Sample size"]]
  n$FARTSSIE[j] <- ceiling(n.2x2x2*(-0.25*pers+1.5))
  n$ABEL[j]     <- sampleN.scABEL(CV = CV[j], design = design,
                                  targetpower = power, theta0 = theta0,
                                  details = FALSE,
                                  print = FALSE)[["Sample size"]]
}
n$CV        <- n$CV*100
names(n)[1] <- "CV (%)"
cat("design:", design, "\n"); print(n, row.names = FALSE)

design: 2x2x4
 CV (%) FARTSSIE ABEL
     25       28   28
     30       40   34
     35       32   34
     40       27   30
     45       25   28
     50       23   28
     55       27   30
     60       31   32
     65       35   36

design: 2x2x3
 CV (%) FARTSSIE ABEL
     25       42   42
     30       60   50
     35       48   50
     40       41   46
     45       38   42
     50       35   42
     55       41   44
     60       47   48
     65       53   54

• Direct expansion of the limits instead of simulations, restriction of the point estimate (within 80.00–125.00%) not taken into account.
  
• Sample size estimated for 2×2×2 design and adapted (i.e., 50% for 4-period full replicates, 75% for three period replicates).