PowerTOST / Power2Stage [🇷 for BE/BA]
❝ […] why there is not selection for 3-ways crossover design in sample size estimate.
Simple: Yung-jin didn’t implement it.

❝ If there are other soft could estimate sample size for 3-ways crossover design?
I recommend package
PowerTOST
.1 These designs are currently supported:- 2 parallel groups (T|R)
- Paired means (TR or RT)
- 2×2×2 crossover (TR|RT)
- 3×3 crossover (Latin Squares ABC|BCA|CAB)
- 3×6×3 crossover (Williams’ design: ABC|ACB|BAC|BCA|CAB|CBA)
- 4×4 crossover (Latin Squares: ABCD|BCDA|CDAB|DABC or any of the Williams’ designs)
- 2×2×3 full replicate (TRT|RTR)
- 2×2×4 full replicate (TRTR|RTRT)
- 2×4×4 full replicate (TRTR|RTRT|TTRR|RRTT)
- 2×3×3 partial replicate (TRR|RTR|RRT)
- 2×4×2 full replicate (Balaam’s design: TR|RT|TT|RR)
- 2×2×2r (Liu’s repeated crossover)
In most functions power can be calculated by the shifted t-distribution (crude approximation), the noncentral t-distribution (like in
bear
), or exact methods (preferred). Details in the online manual.Example for a 3×3 design:
library(PowerTOST)
sampleN.TOST(CV=0.2, theta0=0.95, targetpower=0.8, design="3x3x3")
+++++++++++ Equivalence test - TOST +++++++++++
Sample size estimation
-----------------------------------------------
Study design: 3x3 crossover
log-transformed data (multiplicative model)
alpha = 0.05, target power = 0.8
BE margins = 0.8 ... 1.25
True ratio = 0.95, CV = 0.2
Sample size (total)
n power
18 0.808949
sampleN.TOST(CV=0.2, theta0=0.95, targetpower=0.8, design="2x2x2")
+++++++++++ Equivalence test - TOST +++++++++++
Sample size estimation
-----------------------------------------------
Study design: 2x2 crossover
log-transformed data (multiplicative model)
alpha = 0.05, target power = 0.8
BE margins = 0.8 ... 1.25
True ratio = 0.95, CV = 0.2
Sample size (total)
n power
20 0.834680
If you are interested in Two-Stage Designs (group-sequential and adaptive TSDs with sample size re-estimation: parallel groups and 2×2×2 crossovers) consider package
Power2Stage
.2 Online manual.- Labes D, Schütz H, Lang B. PowerTOST: Power and Sample Size Based on Two One-Sided t-Tests (TOST) for (Bio)Equivalence Studies. 2018-04-12: version 1.4-7. CRAN, GitHub.
- Labes D, Lang B, Schütz H. Power2Stage: Power and Sample-Size Distribution of 2-Stage Bioequivalence Studies. 2018-04-03: version 0.5-1. CRAN, GitHub.
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
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Helmut Schütz
![[image]](https://static.bebac.at/img/CC by.png)
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- about the sample estimator of Bear fyy897854960 2018-10-31 09:13 [🇷 for BE/BA]
- PowerTOST / Power2StageHelmut 2018-10-31 11:08
- PowerTOST / Power2Stage fyy897854960 2018-10-31 13:53
- PowerTOST / Power2StageHelmut 2018-10-31 11:08