IM: Monitoring the trial at interim looks for a trial with...

In HCTDesign: Group Sequential Design for Historical Control Trial with Survival Outcome

Monitoring the trial at interim looks for a trial with efficacy and futility boundaries

Description

Calculates one-sided boundary values at the observed number of events.

Usage

IM(d2, dmax, last.look = FALSE, d1, etam, alpha, beta, opt = "OBF", param = 4)

Arguments

d2	vector of number of events at which you want to monitor the trial.
dmax	maximum number of events in the experimental group calculated from design function.
last.look	logical which indicates whether the current look is the last look or not. Default is FALSE.
d1	total number of events in the historical control group.
etam	value of the drift parameter obtained from design function.
alpha	type I error.
beta	type II error.
opt	type of spending function: "OBF", "Gamma", "Rho" or "Pocock". Default is "OBF".
param	Parameter for Gamma family or Rho family. Default value is 4.

Details

The number of events have to be entered sequentially. See example.

Value

A list containing efficacy and futility boundary values along with the p-values and transformed information time for the current look. Post-hoc power is also calculated in case of early stopping of the trial.

Author(s)

Tushar Patni, Yimei Li, Jianrong Wu, and Arzu Onar-Thomas.

References

\insertRef

doi:10.1002/pst.1756HCTDesign

\insertRef

doi:10.1080/10543406.2019.1684305HCTDesign

Examples

#Interim look for the trial when the number of events is 13(first look).
gg<-IM(c(13),dmax=57,alpha=0.05,beta=0.1,etam=3.0726,d1=65,opt="OBF",last.look=FALSE)
#Interim look for the trial when the number of events is 35(second look).
gg<-IM(c(13,35),dmax=57,alpha=0.05,beta=0.1,etam=3.0726,d1=65,opt="OBF",last.look=FALSE)

HCTDesign documentation built on Aug. 29, 2025, 5:23 p.m.