lgrkPower: Unstratified (ordinary) logrank power
In factorial2x2: Design and Analysis of a 2x2 Factorial Trial
Description
Usage
Arguments
Details
Value
Author(s)
References
Examples
Description
Computes the power for the unstratified (ordinary) logrank statistic
for two group comparison.
Usage
1
lgrkPower(hr, nevent, alpha = 0.05, rprob = 0.5)
Arguments
hr
hazard ratio
nevent
expected number of events
alpha
two-sided significance level
rprob
randomization probability
Details
Uses the formula at the bottom of p.317 from Schoenfeld (Biometrika, 1981)
where the beta should be 1 - beta. The formula is modified
to assume that values of the hazard ratio
less than 1 correspond to treatment efficacy. We do this because we only want
to include the probability of rejecting the null in favor of efficacy, not inferiority
as well.
Value
power
logrank power
Author(s)
Eric Leifer, James Troendle
References
Schoenfeld, D. The asymptotic properties of nonparametric tests for comparing
survival distributions. Biometrika. 1981; 68: 316-319.
Examples
1
2
3
4
5
hr <- 0.5
nevent <- 98
lgrkPower(hr, nevent, alpha = 0.05, rprob = 0.5)
# $power
# [1] 0.9293463
factorial2x2 documentation built on April 28, 2020, 1:09 a.m.
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Description Usage Arguments Details Value Author(s) References Examples
Description
Computes the power for the unstratified (ordinary) logrank statistic for two group comparison.
Usage
1 | lgrkPower(hr, nevent, alpha = 0.05, rprob = 0.5)
|
Arguments
hr |
hazard ratio |
nevent |
expected number of events |
alpha |
two-sided significance level |
rprob |
randomization probability |
Details
Uses the formula at the bottom of p.317 from Schoenfeld (Biometrika, 1981) where the beta should be 1 - beta. The formula is modified to assume that values of the hazard ratio less than 1 correspond to treatment efficacy. We do this because we only want to include the probability of rejecting the null in favor of efficacy, not inferiority as well.
Value
power |
logrank power |
Author(s)
Eric Leifer, James Troendle
References
Schoenfeld, D. The asymptotic properties of nonparametric tests for comparing survival distributions. Biometrika. 1981; 68: 316-319.
Examples
1 2 3 4 5 | hr <- 0.5
nevent <- 98
lgrkPower(hr, nevent, alpha = 0.05, rprob = 0.5)
# $power
# [1] 0.9293463
|
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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