## Non-Superiority [Design Issues]

❝ The goal of an RCT is to compare the difference of complication rates of CVD surgery between two groups (group A and group B).

❝ The patients in group A will take medicine (traditionally treatment) and the patients in group B without taking medicine.

❝

❝ Notably, we want to design the RCT as a non-inferiority trial. That is, the effect of complication rates of patients without taking medicine in group B is not worse than the patients in group A with take medicine.

Hhm.

❝ So, could we design the RCT as a non-inferiority trial?

The other way ’round.

Higher response is considered ‘better’ → Non-Inferiority

Lower response is considered ‘better’ → Non-Superiority

You hope that the complication rates in group A (with medicine) are

*lower*than in group B (without medicine), right? Hence, that’s a Non-

*Superiority*trial.

Note: *x*-axis in log-scale. \(\delta\) made up out of thin air.

❝ Moreover, how to defining the non-inferiority margin at the situation?

You don’t need only to define the non-

*superiority*margin \(\small{\delta}\) but also assume the variability. No idea.

You are dealing with complication rates, which are \(\small{0\leq x \leq 1}\). As an aside, you can’t use the function

`sampleN.noninf()`

of the -package `PowerTOST`

, because it handles only lognormal \((\small{x\in\mathbb{R^{+}}}\)) or normal \((\small{-\infty\leq x+\infty}\)) distributed data. I’m sure, PASS has a fancy method for that.*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:

- Could we design the RCT as a non-inferiority trial at this situation? dennis001 2022-07-24 17:39 [Design Issues]
- Non-SuperiorityHelmut 2022-07-25 16:37
- Non-Superiority dennis001 2022-07-26 02:32
- Non-Superiority Helmut 2022-07-26 15:04
- Non-Superiority dennis001 2022-07-27 05:18
- Placebo effect Helmut 2022-07-27 12:17

- Non-Superiority dennis001 2022-07-27 05:18

- Non-Superiority Helmut 2022-07-26 15:04

- Non-Superiority dennis001 2022-07-26 02:32
- Could we design the RCT as a non-inferiority trial at this situation? ElMaestro 2022-07-26 12:44
- Could we design the RCT as a non-inferiority trial at this situation? dennis001 2022-07-27 05:21

- Non-SuperiorityHelmut 2022-07-25 16:37