| strLgrkPower {factorial2x2} | R Documentation |
Stratified (overall) logrank power
Description
Computes the power for the overall treatment A effect based on the stratified logrank test based on Slud (1994).
Usage
strLgrkPower(n, hrA, hrB, hrAB, avgprob, dig = 2, alpha = 0.05)
Arguments
n |
total subjects with n/4 subjects in the C, A, B, and AB groups |
hrA |
group A to group C hazard ratio |
hrB |
group B to group C hazard ratio |
hrAB |
group AB to group C hazard ratio |
avgprob |
average event probability across the four groups as calculated by the function eventProb |
dig |
number of decimal places to which we |
alpha |
two-sided significance level |
Details
The roundDown function is used in conjunction with the dig argument
to insure that any rounding of the (negative) critical values will be done conservatively to control
the familywise type I error at the desired level.
Value
mean |
logrank mean value |
power |
logrank power |
nevent |
expected number of events |
Author(s)
Eric Leifer, James Troendle
References
Leifer, E.S., Troendle, J.F., Kolecki, A., Follmann, D. Joint testing of overall and simple effect for the two-by-two factorial design. (2019). Submitted.
Slud, E.V. Analysis of factorial survival experiments. Biometrics. 1994; 50: 25-38.
See Also
Examples
rateC <- 0.0445
hrA <- 0.80
hrB <- 0.80
hrAB <- 0.72
mincens <- 4.0
maxcens <- 8.4
avgprob <- eventProb(rateC, hrA, hrB, hrAB, mincens, maxcens)$avgprob
n <- 4600
strLgrkPower(n, hrA, hrB, hrAB, avgprob, dig = 2, alpha = 0.05)
# $mean
# [1] -2.537779
# $power
# [1] 0.7182932
# $nevent
# [1] 954.8738