No ‘R1’ and ‘R2’ in replicate designs [General Statistics]
❝ In a partial replicated design (3-periods, 3 sequences), only reference is replicated, with a sample size of 45, CRO sent to me the following with proc GLM for ANOVA for the R/R comparison:
Least Squares Means:
❝ Also they sent to me the following 90% CI for the comparative R1/R2:
Ratio = 110.79
90% Confidence Interval = 87.31 - 140.57
Intra-subject CV% = 21.18
There can be only one.
There is no ‘R1’ and ‘R2’, only one R repeatedly administered in the sequences in different periods. Say, the sequences are
TRR | RTR | RRT. Did the CRO call the first administration in each sequence R1 and the second R2 (while dropping T)?
This gives after recoding:
░R1R2 | R1░R2 | R1R2░
❝ But I have several doubts:
❝ - It surprises me a 90% CI so wide for a relatively low, at least not high, ISCV.
❝ - If I back-calculated the CV from this 90% CI with “CVfromCI” of PowerTOST, I obtain a CV of around 70%. Why?
CI2CV(lower=0.8731, upper=1.4057, design="2x2x2", n=40), right? That’s not what you have. After recoding (wild guess) you have an Incomplete Block Design. Other degrees of freedom,
❝ - In addition, I have tried to calculate the ratio and 90% CI with MSE and LSM according to the Helmut example from Pamplona lecture on 2018 "Basic Statistic on BE", slide 16 and 17:
❝ I obtained a ratio of 110,8 but a 90% CI of 102,44 – 119,94. Same ratio as CRO but different 90 % CI. This is strange although it is in line with the ISCV presented by the CRO.
CI2CV(). But again, there is only one R. A ‘PE’ and ‘CI’ doesn’t make sense.
❝ Furthermore, doing various tests, … why?
❝ So, what is the correct 90% CI?
If you want, send me the raw data off-list.
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
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- Calculation of PE and 90% CI Brus 2023-06-14 16:34 [General Statistics]