FARTSSIE v2.7 [Software]

posted by Helmut Homepage – Vienna, Austria, 2021-03-11 21:24 (36 d 09:23 ago) – Posting: # 22260
Views: 415

Hi DShah,

» Still struggling with installation of R in organization …

It’t high time for your organization to learn that you need the right tools to perform your job.

I suppose it is tempting, if the only tool you have is a hammer,
to treat everything as if it were a nail.
  Abraham H. Maslow (Toward a Psychology of Being, 1962)

» … and because of that I had asked for Sample size for NTI- FDA method in excel.

You would need to simulate 100,000 studies in each iteration (cause you will not hit the target with a lucky punch). I don’t say that’s impossible in Excel. But why the hell would one do that, if PowerTOST can give you the result in less than a second?

st <- proc.time()[[3]]
sampleN.NTIDFDA(CV = 0.1, theta0 = 0.975, targetpower = 0.8, design = "2x2x4")
cat("Runtime:",  proc.time()[[3]] - st, "seconds\n")

+++++++++++ FDA method for NTIDs ++++++++++++
           Sample size estimation
Study design:  2x2x4 (TRTR|RTRT)
log-transformed data (multiplicative model)
1e+05 studies for each step simulated.

alpha  = 0.05, target power = 0.8
CVw(T) = 0.1, CVw(R) = 0.1
True ratio     = 0.975
ABE limits     = 0.8 ... 1.25
Implied scABEL = 0.8000 ... 1.2500
Regulatory settings: FDA
- Regulatory const. = 1.053605
- 'CVcap'           = 0.2142

Sample size search
 n     power
14   0.717480
16   0.788690
18   0.841790

Runtime: 0.24 seconds

Dif-tor heh smusma 🖖
Helmut Schütz

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