## Bug in PowerTOST:CI.BE [🇷 for BE/BA]

❝ […] I would like to thank you all for contributing to thorough explanations and interesting discussions.

Welcome (also in the name of other members of the forum).

❝ […] I was calculating confidence intervals in R using package PowerTOST and function `CI.BE`

and I think I have noticed a minor mistake in CI calculations when having unbalanced design with odd total number of subjects without defining number of subjects in each sequence. If I am not mistaken, in this case the program incorrectly calculates CI assuming balanced design with half (0.5) of a subject in each sequence and doesnt assume an unbalanced design with small imbalanced as it does in other functions (for example when calculating power using power.TOST).

Oops – THX for discovering a

**bug**! We will correct the function and update the package as soon as possible.

BTW, the problem applies not only to

*odd*total sizes:

`library(PowerTOST)`

pe <- 0.95

CV <- 0.3

# both n1 and n2 are even, same total n

n <- 40

n1 <- seq(20, 30, 2)

n2 <- n - n1

CI <- data.frame(n1 = n1, n2 = n2, lower = NA_real_, upper = NA_real_)

for (i in 1:nrow(CI)) {

CI[i, 3:4] <- CI.BE(pe = pe, CV = CV, n = CI[i, 1:2])

}

print(round(CI, 4), row.names = FALSE)

n1 n2 lower upper

20 20 0.8505 1.0612

22 18 0.8500 1.0618

24 16 0.8485 1.0636

26 14 0.8459 1.0669

28 12 0.8419 1.0719

30 10 0.8360 1.0795

The more imbalanced the design gets, the wider the CI. When we implement ‘best guess’ sequence-/group-sizes like in the other functions, it will still be what it says: A guess (trying to keep the design as balanced as possible).

If you give the total sample size, you will always get the first row of the data frame above,

*i.e.*,

`round(CI.BE(pe = pe, CV = CV, n = n), 4)`

lower upper

0.8505 1.0612

*Dif-tor heh smusma*🖖🏼 Довге життя Україна!

_{}

Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮

Science Quotes

### Complete thread:

- CI.BE in PowerTOST BEQool 2023-03-31 10:05 [🇷 for BE/BA]
- Bug in PowerTOST:CI.BEHelmut 2023-03-31 11:41
- Bug in PowerTOST:CI.BE BEQool 2023-04-03 05:38

- Bug in PowerTOST:CI.BEHelmut 2023-03-31 11:41