## 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:`

❝ `R1: 2.522`

❝ `R2: 2.419`

❝

❝ 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 ‘R

**’ and ‘R**

_{1}**’, only**

_{2}*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 R

_{1}and the second R

_{2}(while dropping T)?

This gives after recoding:

` ░R`_{1}R_{2} | R_{1}░R_{2} | R_{1}R_{2}░

❝ 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?

*CV*

_{wR}according to the EMA’s or the FDA’s models. The results will be similar, though quite often the one of the FDA is a bit smaller.

If you want, send me the raw data off-list.

*Dif-tor heh smusma*🖖🏼 Довге життя Україна!

_{}

Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮

Science Quotes

### Complete thread:

- Calculation of PE and 90% CI Brus 2023-06-14 16:34 [General Statistics]
- No ‘R1’ and ‘R2’ in replicate designsHelmut 2023-06-14 22:26
- No ‘R1’ and ‘R2’ in replicate designs Brus 2023-06-15 14:07
- Rose is a rose is a rose is a rose Helmut 2023-06-15 14:49
- No ‘R1’ and ‘R2’ in replicate designs Achievwin 2023-06-19 19:42

- No ‘R1’ and ‘R2’ in replicate designs Brus 2023-06-15 14:07

- No ‘R1’ and ‘R2’ in replicate designsHelmut 2023-06-14 22:26