Log in
Register2x3x3 or 2x2x3 or 2x2x4? [RSABE / ABEL]
Dear Felipe,
Since your original question refers to FDA lets see:
(using R with package PowerTOST, true GMR=0.95, target power=80%, sample size for reference scaled ABE using scABE criterion according to progesterone guidance)
The number of measurements (concentration samples) are
2x3x3 = 72 * number of timepoints
2x2x3 = 84 * number of timepoints
2x2x4 = 72 * number of timepoints
The design 2x2x3 needs somewhat higher sample size than the partial replicate but has the advantage of yielding also an intra-subject variability for Test. But this is a "nice to have".
Hope this helps.
❝ But talking a little about sample size, ...
Since your original question refers to FDA lets see:
(using R with package PowerTOST, true GMR=0.95, target power=80%, sample size for reference scaled ABE using scABE criterion according to progesterone guidance)
> library(PowerTOST)
> sampleN.RSABE(CV=0.4, design="2x3x3")
++++++++ Reference scaled ABE crit. +++++++++
Sample size estimation
---------------------------------------------
Study design: 2x3x3 (partial replicate)
log-transformed data (multiplicative model)
1e+05 studies for each step simulated.
alpha = 0.05, target power = 0.8
CVw(T) = 0.4; CVw(R) = 0.4
Null (true) ratio = 0.95
ABE limits / PE constraints = 0.8 ... 1.25
Regulatory settings: FDA
- CVswitch = 0.3
- Regulatory constant = 0.8925742
Sample size search
n power
21 0.73975
24 0.80864
> sampleN.RSABE(CV=0.4, design="2x2x3")
++++++++ Reference scaled ABE crit. +++++++++
Sample size estimation
---------------------------------------------
Study design: 2x2x3 (TRT|RTR)
log-transformed data (multiplicative model)
1e+05 studies for each step simulated.
alpha = 0.05, target power = 0.8
CVw(T) = 0.4; CVw(R) = 0.4
Null (true) ratio = 0.95
ABE limits / PE constraints = 0.8 ... 1.25
Regulatory settings: FDA
- CVswitch = 0.3
- Regulatory constant = 0.8925742
Sample size search
n power
20 0.66022
22 0.71427
24 0.76072
26 0.79722
28 0.83092
> sampleN.RSABE(CV=0.4, design="2x2x4")
++++++++ Reference scaled ABE crit. +++++++++
Sample size estimation
---------------------------------------------
Study design: 2x2x4 (full replicate)
log-transformed data (multiplicative model)
1e+05 studies for each step simulated.
alpha = 0.05, target power = 0.8
CVw(T) = 0.4; CVw(R) = 0.4
Null (true) ratio = 0.95
ABE limits / PE constraints = 0.8 ... 1.25
Regulatory settings: FDA
- CVswitch = 0.3
- Regulatory constant = 0.8925742
Sample size search
n power
14 0.68849
16 0.76590
18 0.82274The number of measurements (concentration samples) are
2x3x3 = 72 * number of timepoints
2x2x3 = 84 * number of timepoints
2x2x4 = 72 * number of timepoints
The design 2x2x3 needs somewhat higher sample size than the partial replicate but has the advantage of yielding also an intra-subject variability for Test. But this is a "nice to have".
Hope this helps.
—
Regards,
Detlew
Regards,
Detlew
Complete thread:
- 3x3 or 2x4? felipeberlinski 2014-10-22 14:20 [RSABE / ABEL]
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- 3x3 or 2x4? ElMaestro 2014-10-22 14:42
- 3x3 or 2x4? nobody 2014-10-22 15:06
- 3x3 or 2x4? felipeberlinski 2014-10-22 15:36
- 3x3 or 2x4? nobody 2014-10-22 15:41
- 2x3x3 or 2x2x3 or 2x2x4?d_labes 2014-10-22 16:12
- 2x3x3 or 2x2x3 or 2x2x4? MGR 2015-04-08 13:35
- Sample size for scABE in SAS? d_labes 2015-04-08 16:06
- Re-inventing the wheel Helmut 2015-04-08 16:19
- 2x3x3 or 2x2x3 or 2x2x4? MGR 2015-04-08 13:35
- 3x3 or 2x4? felipeberlinski 2014-10-22 15:36
- 3x3 or 2x4? nobody 2014-10-22 15:06
- RTR|TRT Helmut 2014-10-22 16:36
- 3x3 or 2x4? Mauricio Sampaio 2014-10-28 12:12
- 3x3 or 2x4? ElMaestro 2014-10-22 14:42
Ing. Helmut Schütz