Where do these numbers come from? [Study Assessment]
Hi Mahmoud,
Nope. n=16.
Why 36? For FDA’s RSABE, CV 43.13%, T/R 0.90 (risky to assume a “better” one – even if the pilot suggests so), 80% power:
How did you derive this number? A T/R of 0.9 calls for Montague’s “Method D” (an adjusted α of 0.028). Reference-scaling is not possible in TSDs. One can start the first stage with any number of subjects. A reasonable n1 is ~¾ of the fixed sample design’s n (with α 0.05: 154). With n1 116 power in the first stage is 59.8%, the chance to proceed to the second stage is 39.7%, and overall power is 82.6%. The expected average total sample size is 147. Percentiles of N:
Again: Why 36? Most critical is AUCi with T/R 0.82 (‼) and CV 35.48%. If we believe that these values are true (ha-ha), we would need 146 subjects in a 4-period full replicate. The 36 you suggested would give Unique_One a power of 45.7%. That’s less than the 48.6% winning chance one could expect for betting rouge/noir, pair/impair, manque/passe in roulette. Bad advice.
BTW, the high number is mainly caused by the [0.80–1.25] constraint on the PE. Without (theoretically) we would need 80 subjects.
❝ Dear Sir
▲ Are you sure that Unique_One is male?
❝ 1. For the pilot fating study based on N=18.
Nope. n=16.

❝ The CV in cmax is >30% then we can use 3 way reference replicate scaled with N=36
Why 36? For FDA’s RSABE, CV 43.13%, T/R 0.90 (risky to assume a “better” one – even if the pilot suggests so), 80% power:
design n power
RTRT|TRTR 18 0.82595
RTR|TRT 28 0.83176
RRT|RTR|TRR 24 0.81442
❝ or we can use two -stage 2x2 with N=50
How did you derive this number? A T/R of 0.9 calls for Montague’s “Method D” (an adjusted α of 0.028). Reference-scaling is not possible in TSDs. One can start the first stage with any number of subjects. A reasonable n1 is ~¾ of the fixed sample design’s n (with α 0.05: 154). With n1 116 power in the first stage is 59.8%, the chance to proceed to the second stage is 39.7%, and overall power is 82.6%. The expected average total sample size is 147. Percentiles of N:
min 5% 25% med 75% 95% max
116 116 116 116 184 222 310
min 5% 25% med 75% 95% max
50 50 50 172 206 252 390
❝ 2. For fed study: The problem in GMR is about 87%. So in this case I recommened to genrate your study using the full replicate scaled with N=36
Again: Why 36? Most critical is AUCi with T/R 0.82 (‼) and CV 35.48%. If we believe that these values are true (ha-ha), we would need 146 subjects in a 4-period full replicate. The 36 you suggested would give Unique_One a power of 45.7%. That’s less than the 48.6% winning chance one could expect for betting rouge/noir, pair/impair, manque/passe in roulette. Bad advice.
BTW, the high number is mainly caused by the [0.80–1.25] constraint on the PE. Without (theoretically) we would need 80 subjects.
—
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png)
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. 🚮
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Complete thread:
- 2 way fasting and 3 way fed pilot results analysis unique_one 2015-10-17 09:33 [Study Assessment]
- 2 way fasting and 3 way fed pilot results analysis Mahmoud 2015-11-22 09:51
- Where do these numbers come from?Helmut 2015-11-23 14:01
- Numbers? Helmut 2015-11-23 16:57
- 2 way fasting and 3 way fed pilot results analysis Mahmoud 2015-11-22 09:51