α and 1–β [Power / Sample Size]
Hi Yura,
» If at GMR=0.95 and CV=0.25 calculation has to be carried out at N = 28-30 subjects, and you carry out on 50 subjects, there can be questions on forced bioequivalence
If I got your example correctly, 28–30 subjects mean 81–83% power. In some guidelines 80–90% power are recommended. 90% power would require 38 subjects. 50 subjects would mean 96% power (BE-proff’s “big wallet”).
However, such a sample size should concern only the IEC (assessing the risk for the study participants). If the protocol was approved by the IEC and the competent regulatory agency, performed as planned and by chance show an even higher “power”, an eyebrow of the assessor might be raised but technically (Type I Error is controlled) there is no reason to question the study.
» If at GMR=0.95 and CV=0.25 calculation has to be carried out at N = 28-30 subjects, and you carry out on 50 subjects, there can be questions on forced bioequivalence

If I got your example correctly, 28–30 subjects mean 81–83% power. In some guidelines 80–90% power are recommended. 90% power would require 38 subjects. 50 subjects would mean 96% power (BE-proff’s “big wallet”).
However, such a sample size should concern only the IEC (assessing the risk for the study participants). If the protocol was approved by the IEC and the competent regulatory agency, performed as planned and by chance show an even higher “power”, an eyebrow of the assessor might be raised but technically (Type I Error is controlled) there is no reason to question the study.
—
Cheers,
Helmut Schütz
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The quality of responses received is directly proportional to the quality of the question asked. ☼
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Cheers,
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:
- Power is getting high - kms.srinivas, 2017-12-26 07:39 [Power / Sample Size]
- Power is getting high? - d_labes, 2017-12-26 12:08
- Stop estimating post hoc power! - Helmut, 2017-12-26 12:22
- Stop estimating post hoc power! - kms.srinivas, 2017-12-26 13:00
- Stop estimating post hoc power! - ElMaestro, 2017-12-26 14:11
- Simulations - Helmut, 2017-12-26 15:51
- Simulations - BE-proff, 2017-12-27 06:53
- Simulations - ElMaestro, 2017-12-27 07:25
- Simulations - Yura, 2017-12-27 08:23
- Simulations - kms.srinivas, 2017-12-27 09:11
- Simulations - Yura, 2017-12-27 10:07
- α and 1–β - Helmut, 2017-12-27 12:57
- α and 1–β - Yura, 2017-12-27 13:33
- α and 1–β - Helmut, 2017-12-27 14:31
- α and 1–β - Yura, 2017-12-28 06:50
- Educate the IEC and regulators - Helmut, 2017-12-28 11:30
- α and 1–β - Yura, 2017-12-28 06:50
- α and 1–β - Helmut, 2017-12-27 14:31
- α and 1–β - Yura, 2017-12-27 13:33
- α and 1–β - Helmut, 2017-12-27 12:57
- “Forced BE” 101 - Helmut, 2017-12-27 12:23
- “Forced BE” 101 - kms.srinivas, 2017-12-27 12:41
- Would you be so kind answering our questions? - Helmut, 2017-12-27 13:02
- Would you be so kind answering our questions? - kms.srinivas, 2017-12-28 05:53
- Yes, but why? - Helmut, 2017-12-28 11:47
- Yes, but why? - DavidManteigas, 2017-12-28 16:59
- Optimists and pessimists - Helmut, 2017-12-28 17:33
- "normal" GMR setting - d_labes, 2017-12-28 18:57
- Example for discussion - mittyri, 2017-12-28 22:06
- Example for discussion - Helmut, 2017-12-28 22:33
- I prefer to play it safe - Helmut, 2017-12-28 22:10
- Example for discussion - mittyri, 2017-12-28 22:06
- "normal" GMR setting - d_labes, 2017-12-28 18:57
- Full ACK - d_labes, 2017-12-28 17:41
- About GMR 1.10 - kms.srinivas, 2017-12-29 13:20
- Better 0.95 or 0.90 - Helmut, 2017-12-29 16:18
- Optimists and pessimists - Helmut, 2017-12-28 17:33
- Yes, but why? - Yura, 2017-12-29 13:46
- Buffon's needle - Astea, 2018-01-20 23:55
- Buffon's needle - Oleg777, 2018-10-09 22:48
- 0.95 or 1.05 - Helmut, 2018-10-10 13:41
- Buffon's needle - Helmut, 2018-10-10 12:46
- Buffon's needle - Astea, 2018-10-11 23:14
- School maths - Helmut, 2018-10-12 01:10
- School russian - Astea, 2018-10-12 12:41
- Offtop: Umschrift der westlichen Eigennamen auf Russisch - mittyri, 2018-10-12 23:25
- School maths - Helmut, 2018-10-12 01:10
- Buffon's needle - Astea, 2018-10-11 23:14
- Buffon's needle - Oleg777, 2018-10-09 22:48
- Yes, but why? - DavidManteigas, 2017-12-28 16:59
- Yes, but why? - Helmut, 2017-12-28 11:47
- EEU? - mittyri, 2017-12-28 21:52
- EEU? - Yura, 2017-12-29 13:41
- EEU - pharmacokinetic equation??? - mittyri, 2017-12-29 14:11
- EEU? - Beholder, 2018-01-16 15:10
- EEU? - Yura, 2017-12-29 13:41
- Would you be so kind answering our questions? - kms.srinivas, 2017-12-28 05:53
- Would you be so kind answering our questions? - Helmut, 2017-12-27 13:02
- “Forced BE” 101 - kms.srinivas, 2017-12-27 12:41
- Simulations - Yura, 2017-12-27 10:07
- Simulations - kms.srinivas, 2017-12-27 09:11
- Simulations - xtianbadillo, 2018-01-18 22:22
- Simulations - BE-proff, 2017-12-27 06:53
- Stop estimating post hoc power! - kms.srinivas, 2017-12-26 13:00
- Numbers don't lie - ElMaestro, 2017-12-28 20:13