RARfreq (version 0.1.4)

power_comparison_Power_vs_Trt: Comparison of Powers for Treatment Effects under Different DBCD Randomization Methods (Binary Responses)

Description

Compares the power of a 2-arm design under different treatment effects for the same sample size and placebo effect through matrices and plots.

Usage

power_comparison_Power_vs_Trt(n, nstart, p_pbo, p_trt, nstop,
replication, group_allo, rho_func_index, rho_func, alpha, sig_level)

Value

• Allocation - Average and standard deviation (SD) of allocation distribution

• Estimation - Average and standard deviation of treatment effect

• Power - Average power: 1) Chi-square test, 2) one-sided proportion test performed for each of the k-th arm against H0: p_1>p_k without multiplicity adjustment

• Plot - Three figures of results: 1) Allocation mean and SD, 2) Estimated mean response and SD, 3) Power of Chi-square test and power of one-sided proportion test

Arguments

n

The number of patients. The default is 100.

nstart

Burn-in sample size of each arm. The default is n/20.

p_pbo

Success rate of placebo (control) arm. The default is 0.3.

p_trt

A vector containing success rates of treatment arm.

nstop

A vector of stopping cap of sample size for each arm. The trial stops if at least one arm reaches the corresponding cap. The default is NULL, which means no cap.

replication

the number of replications of the simulation. The default is 100.

group_allo

A number or a vector of group size(s) for allocation. If a number is given, the allocation ratios will be updated for each batch of group_allo samples. If a vector is given, the allocation ratios will be updated sequentially in group according to the vector. Any value greater than n will be omitted. The default is group_allo=1, which is the same as group_allo = seq(nstart*length(p)+1,n).

rho_func_index

Supply a number of 1, 2 or 3 indicting the allocation function to use. 1 = Wei's allocation 2 = Neyman allocation; 3 (default) = Rosenberger allocation;

rho_func

Supply a user-specified allocation function of Mean_RK and SD_RK when rho_func_index is NULL. Default is NULL.

alpha

Supply a number indicating the subscripts of the probability function. The default is 2.

sig_level

Significant level. The default is 0.05.

Details

'power_comparison_Power_vs_Trt' reads different treatment effects and outputs allocation, estimated rates and powers.

Examples

## Default setting
power_comparison_Power_vs_Trt(
n = 100,
nstart = round(100/20),
p_pbo = 0.3,
p_trt = seq(0,0.3,0.1)+0.3,
nstop = NULL,
replication = 5,
group_allo = 1,
rho_func_index = 3,
rho_func = NULL,
alpha = 2,
sig_level = 0.05
)