## Simon’s Two Stage Design Calculator

#### Simon's Two Stage Design

Inputs:

- Null hypothesis proportion (p0): Specify the expected proportion under the null hypothesis.
- Alternative hypothesis proportion (pA): Define the expected proportion under the alternative hypothesis.
- Type II error rate (beta): Set the desired maximum probability of failing to detect a true treatment effect.
- Type I error rate (alpha): Determine the desired level of significance or the probability of incorrectly rejecting the null hypothesis.

Outputs:

- Sample size at Stage 1 (n1): Obtain the optimal sample size for the first stage of the clinical trial.
- Sample size at Stage 2 (n): Determine the optimal sample size for the second stage of the clinical trial.
- Decision boundaries at Stage 1 (r1): Identify the criterion for early termination or continuation of the trial at the first stage based on observed response rates.
- Decision boundaries at Stage 2 (r): Establish the criterion for early termination or continuation of the trial at the second stage based on observed response rates.
- Expected sample size under the null hypothesis (EN(p0)): Calculate the expected sample size assuming the null hypothesis is true.
- Probability of early termination under the null hypothesis (PET (p0)): Determine the probability of early termination assuming the null hypothesis is true.
- Range of admissible probability values (qLo and qHi): Identify the range of probability values for which the particular design is considered admissible.

Note: Click the ‘Download the data’ button to save the results as a .CSV file.

Add ‘.csv’ to the end of the file name to save as a .CSV.

Add ‘.csv’ to the end of the file name to save as a .CSV.