NumEvents {biostatUZH} | R Documentation |
Calculates either the required total number of events or the power.
NumEvents(HR, sig.level=0.05, power=NULL, n.events=NULL, alloc.ratio=1, non.inf.margin=NULL, type="sup", alternative="two.sided")
HR |
Hazard ratio of experimental group vs. control group. |
sig.level |
Significance level. |
power |
Desired power. |
n.events |
Required total number of events. |
alloc.ratio |
Allocation ratio: Ratio of the number of patients in the experimental group divided by the number of patients in the control group. |
non.inf.margin |
Non-inferiority margin. |
type |
Study type. Either "sup" or "superiority" for superiority studies or "noninf" or "non-inferiority" for non-inferiority studies. Default is "sup". |
alternative |
In c("one.sided","two.sided"), depending on whether the alternative hypothesis is one- or two-sided. |
Returns either the required total number of events or the power.
Uriah Daugaard and Leonhard Held
leonhard.held@uzh.ch
Collett, D. (2015). Modelling Survival Data in Medical Research. New York: Chapman and Hall/CRC.
Schoenfeld, D.A. (1983). Sample-Size Formula for the Proportional-Hazards Regression Model. Biometrics, 39, 499–503.
NumEvents(HR = 0.65, sig.level = 0.05, power = 0.9, alloc.ratio = 1, type = "sup", alternative = "two.sided")