LRT {OneArm2stage}

Conduct the Interim or Final Analysis Using the One-Sample Log-Rank Test for Two-Stage TTE Trials

Description

Performs the one-sample log-rank test (OSLR) for the time-to-event data from two-stage Phase II clinical trials assuming the failure time follows a Weibull distribution. This can be used for designs with either unrestricted or restricted follow-up .

Usage

LRT(shape, S0, x0, data)

Arguments

shape

shape parameter for the Weibull distribution.

S0

the survival probability at a fixed time point x0 under the null hypothesis.

x0

a fixed time point when the survival probability is S0 under null.

data

the time-to-event data for either the interim or final analysis from a two-stage survival trial, contains 2 variables:
time the time period under observation before the time of interim analysis (for interim analysis) or during entire trial (for final analysis) for each patient.
status the status indicator of patients (event = 1, censored = 0).

Value

z the OSLR test statistic for the interim or final analysis, depending on data used.
O the observed number of events.
E the expected number of events.

References

Wu, J, Chen L, Wei J, Weiss H, Chauhan A. (2020). Two-stage phase II survival trial design. Pharmaceutical Statistics. 2020;19:214-229. https://doi.org/10.1002/pst.1983

Examples

dat<- read.csv(system.file("extdata", "kj1_final.csv", package = "OneArm2stage"))
LRT(shape=1, S0=0.62, x0=2, data=dat)
# O       E       Z
# 18.0000 16.3598 -0.4055