esDesign (version 1.0.3)

AED2_SSR.CP: Calculate the \(N2\) and the critical value \(C\) in the Adaptive Enrichment Design (Strategy 2) with Sample Size Re-estimation Procedure

Description

The AED2_SSR.CP() is used to calculate the sample size required at the second stage and the critical value used at the final analysis in the Adaptive Enrichment Design with Sample Size Re-estimation Procedure. In addition, this function can also used to conduct the conditional power analysis in terms of \(N2\)

Usage

AED2_SSR.CP(
  Z1 = NULL,
  delta = NULL,
  N1 = NULL,
  pstar,
  rho,
  epsilon,
  alpha,
  beta,
  N2 = NULL
)

Arguments

Z1

The test statistic obtained at the interim analysis

delta

The standardized size of treatment effect, which can be estimated by using \((\mu_{X} - \mu_{Y})/\sqrt{\sigma^2}\).

N1

The sample size used at the first stage

pstar

The (1 - power) of accepting the null hypothesis at the interim analysis.

rho

The proportion of subgroup 1

epsilon

The threshold of the difference between subgroup-specific test statistics.

alpha

The overall Type I error rate

beta

The (1 - Power)

N2

The pre-specified sample size used at the second stage, which is used to conduct the conditional power analysis

Value

A list contains

• upper.boundary The efficacy stopping boundary

• lower.boundary The futility stopping boundary

• N2 The pre-specified sample size used at the second stage, which is used to implement the conditional power analysis

• Conditional.Power The value of conditional power given the value of N2 in the conditional power analysis

• P.Value The corresponding P-Value used at the final analysis in the conditional power analysis

• N2.CP The re-estimated sample size of N2 to ensure an adequate conditional power

• c.CP The estimated the critical value used at the final analysis based the conditional power

Examples

# NOT RUN {
Z1 <- 1.974
delta <- 0.355
N1 <- 248
pstar <- 0.15
alpha <- 0.05
rho <- 0.5
epsilon <- 0.5
beta <- 0.20
N2 <- 104
res <- AED2_SSR.CP(Z1 = Z1, delta = delta, N1 = N1, pstar = pstar,
           alpha = alpha, rho = rho, epsilon = epsilon,
           beta = beta, N2 = N2)

# }