IM {HCTDesign} | R Documentation |
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
Wu J, Xiong X (2016). “Survival trial design and monitoring using historical controls.” Pharmaceutical Statistics, 15(5), 405-411.
Wu J, Li Y (2020). “Group sequential design for historical control trials using error spending functions.” Journal of Biopharmaceutical Statistics, 30(2), 351-363.
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)