CVwR = CVwT < CVw‽ [Power / Sample Size]
❝ Practically I agree with everyone of you.
❝ Nevertheless I have one nitpicker's question.
Being a nitpicker myself I love it.
❝ We have to assume CVwT = CVwR = CVw? (If we design a replicate study for EMA based on the CVw of a 2×2×2 crossover.)
❝ Or CVw can't differ when CVwT = CVwR?
❝ Theoretically I can imagine (no real) data of 2x2x4 replicate study - see following idea: […]
See my simulated data. I hope I got it right.
subject sequence period treatment data
1 TRTR 1 T 0.90180
1 TRTR 2 R 1.10889
1 TRTR 3 T 0.94490
1 TRTR 4 R 1.05831
2 TRTR 1 T 0.96150
2 TRTR 2 R 1.04004
2 TRTR 3 T 0.95560
2 TRTR 4 R 1.04646
3 TRTR 1 T 0.99610
3 TRTR 2 R 1.00392
3 TRTR 3 T 0.97080
3 TRTR 4 R 1.03008
4 TRTR 1 T 0.96760
4 TRTR 2 R 1.03348
4 TRTR 3 T 0.99630
4 TRTR 4 R 1.00371
5 TRTR 1 T 0.96270
5 TRTR 2 R 1.03875
5 TRTR 3 T 0.91270
5 TRTR 4 R 1.09565
6 TRTR 1 T 0.91130
6 TRTR 2 R 1.09733
6 TRTR 3 T 0.94770
6 TRTR 4 R 1.05519
7 RTRT 1 R 1.03530
7 RTRT 2 T 0.96590
7 RTRT 3 R 1.05250
7 RTRT 4 T 0.95012
8 RTRT 1 R 1.07220
8 RTRT 2 T 0.93266
8 RTRT 3 R 1.02920
8 RTRT 4 T 0.97163
9 RTRT 1 R 1.04180
9 RTRT 2 T 0.95988
9 RTRT 3 R 1.07010
9 RTRT 4 T 0.93449
10 RTRT 1 R 1.00270
10 RTRT 2 T 0.99731
10 RTRT 3 R 1.09080
10 RTRT 4 T 0.91676
11 RTRT 1 R 1.00190
11 RTRT 2 T 0.99810
11 RTRT 3 R 1.08120
11 RTRT 4 T 0.92490
12 RTRT 1 R 1.01090
12 RTRT 2 T 0.98922
12 RTRT 3 R 1.06340
12 RTRT 4 T 0.94038
❝ So GMR T/R of all "pooled" data will be close to 0.95/(1/0.95)=0.95^2=0.9025 …
GLSM 0.9542 (T), 1.0480 (R), PE 0.9104.
❝ … and CVw used for CI calculation will be higher than CVwT and CVwR?
CVs (calculated by the EMA’s fixed effects “Method A”): CVwT = CVwR = 3.04%, CVw = 3.42%. Pooled CV larger the ones of T and R. Simply amazing!
❝ I know, in this kind of example the CVwT and CVwR are extremely low, but the point is that theoretically the CVw observed in 2x2 study can be higher than 30% (so we can try replicate design with possible widening of BE acceptance criteria) but the CVwT and CVwR (which we don't know from 2x2) can be lower.
❝ Fact or Fiction?
The former?
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:
- Estimation within-subject CV Mikkabel 2017-07-07 10:13 [Power / Sample Size]
- Estimation within-subject CV ElMaestro 2017-07-07 10:17
- CVwR ~ CVwT ~ CVw? Helmut 2017-07-07 16:09
- CVwR ~ CVwT ~ CVw? zizou 2017-07-08 15:29
- CVwR = CVwT < CVw‽Helmut 2017-07-08 16:45
- 'whatif' plotting from 4X2 to 2X2 mittyri 2017-07-08 23:47
- CVwR ~ CVwT ~ CVw? ElMaestro 2017-07-09 00:16
- CVwR ~ CVwT ~ CVw? zizou 2017-07-09 02:13
- CVwR = CVwT < CVw‽Helmut 2017-07-08 16:45
- CVwR ~ CVwT ~ CVw? zizou 2017-07-08 15:29