RARfreq (version 0.1.4)

power_comparison_Power_vs_Trt_GAUSSIAN: Comparison of Powers for Treatment Effects under Different DBCD Randomization methods (Gaussian 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_GAUSSIAN(n, nstart, mu_pbo, sd_pbo,
mu_trt, sd_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) ANOVA test, 2) one-sided Welch T-test performed for each of the k-th arm against H0: mu_1>mu_k without multiplicity adjustment

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

Arguments

n

The number of patients. Default is 100.

nstart

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

mu_pbo

Mean response of placebo (control) arm. Default is 4.5.

sd_pbo

Response standard deviation of placebo (control) arm. Default is 1.32.

mu_trt

A vector containing mean responses of treatment.

sd_trt

A vector containing response standard deviations of treatment.

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 or 2 indicting the allocation function to use. 1 = Zhang-Rosenberger allocation (2-arm allocation only); 2 (default) = Neyman 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. Default is 2.

sig_level

Significant level. Default is 0.05.

Details

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

Examples

## Default setting
power_comparison_Power_vs_Trt_GAUSSIAN(
n = 100,
nstart = round(100/20),
mu_pbo = 4.5,
sd_pbo = 1.32,
mu_trt = seq(0,0.6,0.2)+4.5,
sd_trt = rep(1.32,4),
nstop = NULL,
replication = 5,
group_allo = 1,
rho_func_index = 2,
rho_func = NULL,
alpha = 2,
sig_level = 0.05
)