Loss in power [Regulatives / Guidelines]
R-code to estimate the loss in power (two groups of equal size). Example for my simulations above and assuming that we will get a significant Group-by-Treatment interaction at the level of the test.
library(PowerTOST)
CV <- 0.3
theta0 <- 1
targetpower <- 0.8
p.level <- 0.1
res <- sampleN.TOST(CV=CV, theta0=theta0, targetpower=targetpower,
print=FALSE)
N <- res[["Sample size"]]
if (N >= 12) { # at least minimum sample size acc. to GLs?
pwr.mod3pooled <- res[["Achieved power"]]
} else {
N <- 12
pwr.mod3pooled <- power.TOST(CV=CV, theta0=theta0, n=N)
}
pwr.mod2 <- suppressMessages(power.TOST(CV=CV, theta0=theta0,
n=N-1)*(1-p.level))
pwr.mod3groups <- power.TOST(CV=CV, theta0=theta0, n=N/2)*p.level
pwr.mod2and3 <- pwr.mod2+pwr.mod3groups
cat(sprintf("CV %5.3f%%, theta0 %.4f, targetpower %.2f%% : sample size %i",
100*CV, theta0, 100*targetpower, N),
"\nLevel of the G\u00D7T test (model 1) :",
sprintf("% 6.4f", p.level),
"\nPower of studies evaluated by model 2 (pooled) :",
sprintf("%5.2f%%", 100*pwr.mod2),
"\nPower of studies evaluated by model 3 (groups) :",
sprintf("%5.2f%%", 100*pwr.mod3groups),
"\nModel 2 (pooled) and 3 (groups) combined :",
sprintf("%5.2f%%", 100*pwr.mod2and3),
"\nPower of studies evaluated by model 3 (pooled) :",
sprintf("%5.2f%%", 100*pwr.mod3pooled),
"\nLoss in power if simple model 3 cannot be applied:",
sprintf("%5.2f%%", 100*(pwr.mod3pooled-pwr.mod2and3)), "\n")
CV 30.000%, theta0 1.0000, targetpower 80.00% : sample size 32
Level of the G×T test (model 1) : 0.1000
Power of studies evaluated by model 2 (pooled) : 71.80%
Power of studies evaluated by model 3 (groups) : 3.25%
Model 2 (pooled) and 3 (groups) combined : 75.05%
Power of studies evaluated by model 3 (pooled) : 81.52%
Loss in power if simple model 3 cannot be applied: 6.47%
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
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Helmut Schütz
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The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- Russian «Экспертами» and their hobby Helmut 2017-04-29 00:46 [Regulatives / Guidelines]
- Low power of Group-by-Treatment interaction mittyri 2017-04-29 22:57
- Let’s forget the Group-by-Treatment interaction, please! Helmut 2017-04-30 13:54
- Let’s forget the Group-by-Treatment interaction, please! ElMaestro 2017-05-01 16:19
- Some answers Helmut 2017-05-02 01:10
- Some answers ElMaestro 2017-05-02 09:04
- Example Helmut 2017-05-02 12:35
- Sensitivity of term? mittyri 2017-05-02 18:29
- Simulations Helmut 2017-05-05 14:38
- loosing specificity due to low sensitivity mittyri 2017-05-08 23:28
- loosing specificity due to low sensitivity Helmut 2017-05-09 00:55
- loosing specificity due to low sensitivity mittyri 2017-05-08 23:28
- Loss in powerHelmut 2017-05-06 17:31
- Interval between groups Helmut 2017-05-08 19:02
- IMP handling mittyri 2017-05-08 23:40
- IMP handling Helmut 2017-05-09 01:08
- IMP handling mittyri 2017-05-08 23:40
- Loss in power Helmut 2017-05-14 17:22
- Simulations Helmut 2017-05-05 14:38
- Some answers ElMaestro 2017-05-02 09:04
- No convergence in JMP and Phoenix WinNonlin Helmut 2017-05-25 15:26
- Ouch?!??? ElMaestro 2017-05-25 16:24
- Some answers Helmut 2017-05-02 01:10
- Let’s forget the Group-by-Treatment interaction, please! ElMaestro 2017-05-01 16:19
- Let’s forget the Group-by-Treatment interaction, please! Helmut 2017-04-30 13:54
- Russian «Экспертами» and their hobby Artem Gusev 2017-05-02 16:13
- be careful with mixed models mittyri 2017-05-02 17:53
- be careful with mixed models Artem Gusev 2017-05-03 11:02
- p-value(s) in model 2 Helmut 2017-05-05 14:48
- be careful with mixed models mittyri 2017-05-02 17:53
- Russian «Экспертами» following the EEU GLs Helmut 2017-05-24 20:17
- Russian «Экспертами» following the EEU GLs Beholder 2017-05-24 22:37
- Penalty for carelessness mittyri 2017-05-25 08:52
- Russian «Экспертами» following the EEU GLs Beholder 2017-05-25 10:43
- Russian «Экспертами» following the EEU GLs Mikalai 2018-01-04 10:43
- Belarus = member of the EEU Helmut 2018-01-04 13:08
- Belarus = member of the EEU Mikalai 2018-01-04 19:49
- Trying your model for EEU mittyri 2018-01-04 22:04
- Trying your model for EEU Helmut 2018-01-05 00:06
- help us to stop it, please... Astea 2018-01-10 12:09
- help us to stop it, please... Beholder 2018-01-10 12:49
- regulators convinced by science? d_labes 2018-01-10 15:15
- regulators convinced by science? Beholder 2018-01-10 17:14
- Чёрт побери! d_labes 2018-01-10 18:53
- regulators convinced by science? Astea 2018-01-10 19:10
- regulators convinced by science? Beholder 2018-01-10 17:14
- help us to stop it, please... Astea 2018-01-10 12:09
- Trying your model for EEU Helmut 2018-01-05 00:06
- Belarus = member of the EEU Helmut 2018-01-04 13:08
- Russian «Экспертами» following the EEU GLs Beholder 2017-05-24 22:37
- Low power of Group-by-Treatment interaction mittyri 2017-04-29 22:57