Survival Noninferiority

Program Code

The program is written in JavaScript.

Source

The program uses the following formula for the total sample size

N=(q(1-alpha)+q(Power))**2*Sum [1/(fi*ei)]/Delta**2

Where fi is the proportion of the sample in treatment i and ei are the event probabilities in treatment i, q is the inverse normal function and

Delta=log(HR(exp./std.)/HREquiv(exp./std.) )

Where HR(exp./std.) is the hazard ratio between the experimental and standard treatments and HREquiv(exp./std.) is the hazard ratio defining noninferiority.

Input Items

The user is prompted for values to the following items. For items that have initial default values set, the values are given in parentheses.

Significance level (.05)
One-sided test
Accrual Period
Follow-up Period after Accrual Period
Competing Risk: the hazard rate of the competing risk random variable
Hazard rate for experimental treatment
Hazard ratios between experimental and standard. [HR(exp./std.)]
Hazard ratios between experimental and standard defining noninferiority. [HREquiv(exp./std.)]
Desired power for sample size estimation or total sample size for power estimation