| power_comparison_Power_vs_Trt {RARfreq} | R Documentation |
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)
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.
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
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
)