EffDesign {HCTDesign}

HCT design with interim monitoring for efficacy only

Description

The group sequential design for historical controlled survival outcome trials with efficacy boundaries only.

Usage

EffDesign(
  k,
  alpha,
  beta,
  delta,
  delta0,
  d1,
  option = "OBF",
  param = 4,
  trial = "Superiority"
)

Arguments

k

vector of time fraction for all planned looks: k=c(1/3,2/3,1) if the three planned looks will be carried out at 1/3, 2/3 and all of the total events in the experiment arm.

alpha

type I error.

beta

type II error.

delta

hazard ratio: hazard of experiment group over hazard of control group.

delta0

Non-inferiority margin.

d1

total number of events in the historical control group.

option

type of spending function: "OBF", "Gamma", "Rho" or "Pocock". Default is "OBF.

param

Parameter for Gamma family or Rho family. Default value is 4.

trial

Type of trial: "Superiority" or "Non-inferiority". Default is "Superiority".

Value

List of dataframes and vectors containing the details about the following: design of the trial which includes the number of looks and events; details about futility and efficacy boundaries which include transformed information time at each look, cumulative beta and alpha respectively, p-values and crossing probabilities; etam(drift parameter); d2max(maximum number of events in the experimental group); delta_used(hazard ratio used in the design).

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

#Superiority trial with three equally spaced looks for efficacy using OBF spending function.
gg<-EffDesign(k=c(0.3,0.6,1),alpha=0.05,beta=0.1,delta=0.57,d1=65,option="OBF",trial="Superiority")